Auto merge of #100668 - nnethercote:use-AttrVec-more, r=spastorino

Use `AttrVec` more

In some places we use `Vec<Attribute>` and some places we use
`ThinVec<Attribute>` (a.k.a. `AttrVec`). This results in various points
where we have to convert between `Vec` and `ThinVec`.

This commit changes the places that use `Vec<Attribute>` to use
`AttrVec`. A lot of this is mechanical and boring, but there are
some interesting parts:
- It adds a few new methods to `ThinVec`.
- It implements `MapInPlace` for `ThinVec`, and introduces a macro to
  avoid the repetition of this trait for `Vec`, `SmallVec`, and
  `ThinVec`.

Overall, it makes the code a little nicer, and has little effect on
performance. But it is a precursor to removing
`rustc_data_structures::ThinVec` and replacing it with
`thin_vec::ThinVec`, which is implemented more efficiently.

r? `@spastorino`

1 files changed, 67 insertions, 67 deletions

diff --git a/src/test/ui/stats/hir-stats.stderr b/src/test/ui/stats/hir-stats.stderr
index 61cb7b25e49..eb828bb9a2c 100644
--- a/src/test/ui/stats/hir-stats.stderr
+++ b/src/test/ui/stats/hir-stats.stderr
@@ -4,58 +4,58 @@ PRE EXPANSION AST STATS
 Name                Accumulated Size         Count     Item Size
 ----------------------------------------------------------------
 ExprField                 48 ( 0.6%)             1            48
-Attribute                 64 ( 0.7%)             2            32
+Crate                     56 ( 0.7%)             1            56
+Attribute                 64 ( 0.8%)             2            32
 - Normal                    32 ( 0.4%)             1
 - DocComment                32 ( 0.4%)             1
-GenericArgs               64 ( 0.7%)             1            64
-- AngleBracketed            64 ( 0.7%)             1
-Local                     72 ( 0.8%)             1            72
-WherePredicate            72 ( 0.8%)             1            72
-- BoundPredicate            72 ( 0.8%)             1
-Crate                     72 ( 0.8%)             1            72
+GenericArgs               64 ( 0.8%)             1            64
+- AngleBracketed            64 ( 0.8%)             1
+Local                     72 ( 0.9%)             1            72
+WherePredicate            72 ( 0.9%)             1            72
+- BoundPredicate            72 ( 0.9%)             1
 Arm                       96 ( 1.1%)             2            48
-ForeignItem              112 ( 1.3%)             1           112
-- Fn                       112 ( 1.3%)             1
-FieldDef                 160 ( 1.8%)             2            80
-Stmt                     160 ( 1.8%)             5            32
+ForeignItem               96 ( 1.1%)             1            96
+- Fn                        96 ( 1.1%)             1
+FieldDef                 160 ( 1.9%)             2            80
+Stmt                     160 ( 1.9%)             5            32
 - Local                     32 ( 0.4%)             1
 - MacCall                   32 ( 0.4%)             1
 - Expr                      96 ( 1.1%)             3
-Param                    160 ( 1.8%)             4            40
-FnDecl                   200 ( 2.3%)             5            40
+Param                    160 ( 1.9%)             4            40
+FnDecl                   200 ( 2.4%)             5            40
 Variant                  240 ( 2.8%)             2           120
-Block                    288 ( 3.3%)             6            48
-GenericBound             352 ( 4.0%)             4            88
-- Trait                    352 ( 4.0%)             4
-AssocItem                480 ( 5.5%)             4           120
-- TyAlias                  240 ( 2.8%)             2
-- Fn                       240 ( 2.8%)             2
-GenericParam             520 ( 6.0%)             5           104
-PathSegment              720 ( 8.3%)            30            24
-Expr                     832 ( 9.6%)             8           104
+Block                    288 ( 3.4%)             6            48
+GenericBound             352 ( 4.2%)             4            88
+- Trait                    352 ( 4.2%)             4
+AssocItem                416 ( 4.9%)             4           104
+- TyAlias                  208 ( 2.5%)             2
+- Fn                       208 ( 2.5%)             2
+GenericParam             520 ( 6.1%)             5           104
+PathSegment              720 ( 8.5%)            30            24
+Expr                     832 ( 9.8%)             8           104
 - Path                     104 ( 1.2%)             1
 - Match                    104 ( 1.2%)             1
 - Struct                   104 ( 1.2%)             1
-- Lit                      208 ( 2.4%)             2
-- Block                    312 ( 3.6%)             3
-Pat                      840 ( 9.7%)             7           120
+- Lit                      208 ( 2.5%)             2
+- Block                    312 ( 3.7%)             3
+Pat                      840 ( 9.9%)             7           120
 - Struct                   120 ( 1.4%)             1
 - Wild                     120 ( 1.4%)             1
-- Ident                    600 ( 6.9%)             5
-Ty                     1_344 (15.5%)            14            96
+- Ident                    600 ( 7.1%)             5
+Ty                     1_344 (15.9%)            14            96
 - Rptr                      96 ( 1.1%)             1
 - Ptr                       96 ( 1.1%)             1
-- ImplicitSelf             192 ( 2.2%)             2
-- Path                     960 (11.0%)            10
-Item                   1_800 (20.7%)             9           200
-- Trait                    200 ( 2.3%)             1
-- Enum                     200 ( 2.3%)             1
-- ForeignMod               200 ( 2.3%)             1
-- Impl                     200 ( 2.3%)             1
-- Fn                       400 ( 4.6%)             2
-- Use                      600 ( 6.9%)             3
+- ImplicitSelf             192 ( 2.3%)             2
+- Path                     960 (11.4%)            10
+Item                   1_656 (19.6%)             9           184
+- Trait                    184 ( 2.2%)             1
+- Enum                     184 ( 2.2%)             1
+- ForeignMod               184 ( 2.2%)             1
+- Impl                     184 ( 2.2%)             1
+- Fn                       368 ( 4.4%)             2
+- Use                      552 ( 6.5%)             3
 ----------------------------------------------------------------
-Total                  8_696
+Total                  8_456
 
 
 POST EXPANSION AST STATS
@@ -63,15 +63,15 @@ POST EXPANSION AST STATS
 Name                Accumulated Size         Count     Item Size
 ----------------------------------------------------------------
 ExprField                 48 ( 0.5%)             1            48
+Crate                     56 ( 0.6%)             1            56
 GenericArgs               64 ( 0.7%)             1            64
 - AngleBracketed            64 ( 0.7%)             1
 Local                     72 ( 0.8%)             1            72
 WherePredicate            72 ( 0.8%)             1            72
 - BoundPredicate            72 ( 0.8%)             1
-Crate                     72 ( 0.8%)             1            72
 Arm                       96 ( 1.0%)             2            48
-ForeignItem              112 ( 1.2%)             1           112
-- Fn                       112 ( 1.2%)             1
+ForeignItem               96 ( 1.0%)             1            96
+- Fn                        96 ( 1.0%)             1
 InlineAsm                120 ( 1.3%)             1           120
 Attribute                128 ( 1.4%)             4            32
 - DocComment                32 ( 0.3%)             1
@@ -82,42 +82,42 @@ Stmt                     160 ( 1.7%)             5            32
 - Semi                      32 ( 0.3%)             1
 - Expr                      96 ( 1.0%)             3
 Param                    160 ( 1.7%)             4            40
-FnDecl                   200 ( 2.1%)             5            40
-Variant                  240 ( 2.5%)             2           120
-Block                    288 ( 3.0%)             6            48
-GenericBound             352 ( 3.7%)             4            88
-- Trait                    352 ( 3.7%)             4
-AssocItem                480 ( 5.1%)             4           120
-- TyAlias                  240 ( 2.5%)             2
-- Fn                       240 ( 2.5%)             2
-GenericParam             520 ( 5.5%)             5           104
-PathSegment              792 ( 8.4%)            33            24
-Pat                      840 ( 8.9%)             7           120
+FnDecl                   200 ( 2.2%)             5            40
+Variant                  240 ( 2.6%)             2           120
+Block                    288 ( 3.1%)             6            48
+GenericBound             352 ( 3.8%)             4            88
+- Trait                    352 ( 3.8%)             4
+AssocItem                416 ( 4.5%)             4           104
+- TyAlias                  208 ( 2.3%)             2
+- Fn                       208 ( 2.3%)             2
+GenericParam             520 ( 5.7%)             5           104
+PathSegment              792 ( 8.6%)            33            24
+Pat                      840 ( 9.1%)             7           120
 - Struct                   120 ( 1.3%)             1
 - Wild                     120 ( 1.3%)             1
-- Ident                    600 ( 6.3%)             5
-Expr                     936 ( 9.9%)             9           104
+- Ident                    600 ( 6.5%)             5
+Expr                     936 (10.2%)             9           104
 - Path                     104 ( 1.1%)             1
 - Match                    104 ( 1.1%)             1
 - Struct                   104 ( 1.1%)             1
 - InlineAsm                104 ( 1.1%)             1
-- Lit                      208 ( 2.2%)             2
-- Block                    312 ( 3.3%)             3
-Ty                     1_344 (14.2%)            14            96
+- Lit                      208 ( 2.3%)             2
+- Block                    312 ( 3.4%)             3
+Ty                     1_344 (14.6%)            14            96
 - Rptr                      96 ( 1.0%)             1
 - Ptr                       96 ( 1.0%)             1
-- ImplicitSelf             192 ( 2.0%)             2
-- Path                     960 (10.2%)            10
-Item                   2_200 (23.3%)            11           200
-- Trait                    200 ( 2.1%)             1
-- Enum                     200 ( 2.1%)             1
-- ExternCrate              200 ( 2.1%)             1
-- ForeignMod               200 ( 2.1%)             1
-- Impl                     200 ( 2.1%)             1
-- Fn                       400 ( 4.2%)             2
-- Use                      800 ( 8.5%)             4
+- ImplicitSelf             192 ( 2.1%)             2
+- Path                     960 (10.5%)            10
+Item                   2_024 (22.0%)            11           184
+- Trait                    184 ( 2.0%)             1
+- Enum                     184 ( 2.0%)             1
+- ExternCrate              184 ( 2.0%)             1
+- ForeignMod               184 ( 2.0%)             1
+- Impl                     184 ( 2.0%)             1
+- Fn                       368 ( 4.0%)             2
+- Use                      736 ( 8.0%)             4
 ----------------------------------------------------------------
-Total                  9_456
+Total                  9_184
 
 
 HIR STATS