Use `token::Lit` in `ast::ExprKind::Lit`.

Instead of `ast::Lit`.

Literal lowering now happens at two different times. Expression literals
are lowered when HIR is crated. Attribute literals are lowered during
parsing.

This commit changes the language very slightly. Some programs that used
to not compile now will compile. This is because some invalid literals
that are removed by `cfg` or attribute macros will no longer trigger
errors. See this comment for more details:
https://github.com/rust-lang/rust/pull/102944#issuecomment-1277476773

2 files changed, 29 insertions, 43 deletions

diff --git a/src/test/ui/parser/bad-lit-suffixes.rs b/src/test/ui/parser/bad-lit-suffixes.rs
index 58b30872677..8cb9ef7e0c9 100644
--- a/src/test/ui/parser/bad-lit-suffixes.rs
+++ b/src/test/ui/parser/bad-lit-suffixes.rs
@@ -28,12 +28,11 @@ fn main() {
 }
 
 #[rustc_dummy = "string"suffix]
-//~^ ERROR suffixes on string literals are invalid
+//~^ ERROR unexpected expression: `"string"suffix`
 fn f() {}
 
 #[must_use = "string"suffix]
-//~^ ERROR suffixes on string literals are invalid
-//~^^ ERROR malformed `must_use` attribute input
+//~^ ERROR unexpected expression: `"string"suffix`
 fn g() {}
 
 #[link(name = "string"suffix)]
diff --git a/src/test/ui/parser/bad-lit-suffixes.stderr b/src/test/ui/parser/bad-lit-suffixes.stderr
index 14c0eda81be..756f99ab12c 100644
--- a/src/test/ui/parser/bad-lit-suffixes.stderr
+++ b/src/test/ui/parser/bad-lit-suffixes.stderr
@@ -10,6 +10,32 @@ error: suffixes on string literals are invalid
 LL |     "C"suffix
    |     ^^^^^^^^^ invalid suffix `suffix`
 
+error: unexpected expression: `"string"suffix`
+  --> $DIR/bad-lit-suffixes.rs:30:17
+   |
+LL | #[rustc_dummy = "string"suffix]
+   |                 ^^^^^^^^^^^^^^
+
+error: unexpected expression: `"string"suffix`
+  --> $DIR/bad-lit-suffixes.rs:34:14
+   |
+LL | #[must_use = "string"suffix]
+   |              ^^^^^^^^^^^^^^
+
+error: suffixes on string literals are invalid
+  --> $DIR/bad-lit-suffixes.rs:38:15
+   |
+LL | #[link(name = "string"suffix)]
+   |               ^^^^^^^^^^^^^^ invalid suffix `suffix`
+
+error: invalid suffix `suffix` for number literal
+  --> $DIR/bad-lit-suffixes.rs:42:41
+   |
+LL | #[rustc_layout_scalar_valid_range_start(0suffix)]
+   |                                         ^^^^^^^ invalid suffix `suffix`
+   |
+   = help: the suffix must be one of the numeric types (`u32`, `isize`, `f32`, etc.)
+
 error: suffixes on string literals are invalid
   --> $DIR/bad-lit-suffixes.rs:12:5
    |
@@ -110,44 +136,5 @@ LL |     1.0e10suffix;
    |
    = help: valid suffixes are `f32` and `f64`
 
-error: suffixes on string literals are invalid
-  --> $DIR/bad-lit-suffixes.rs:30:17
-   |
-LL | #[rustc_dummy = "string"suffix]
-   |                 ^^^^^^^^^^^^^^ invalid suffix `suffix`
-
-error: suffixes on string literals are invalid
-  --> $DIR/bad-lit-suffixes.rs:34:14
-   |
-LL | #[must_use = "string"suffix]
-   |              ^^^^^^^^^^^^^^ invalid suffix `suffix`
-
-error: malformed `must_use` attribute input
-  --> $DIR/bad-lit-suffixes.rs:34:1
-   |
-LL | #[must_use = "string"suffix]
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-help: the following are the possible correct uses
-   |
-LL | #[must_use = "reason"]
-   |
-LL | #[must_use]
-   |
-
-error: suffixes on string literals are invalid
-  --> $DIR/bad-lit-suffixes.rs:39:15
-   |
-LL | #[link(name = "string"suffix)]
-   |               ^^^^^^^^^^^^^^ invalid suffix `suffix`
-
-error: invalid suffix `suffix` for number literal
-  --> $DIR/bad-lit-suffixes.rs:43:41
-   |
-LL | #[rustc_layout_scalar_valid_range_start(0suffix)]
-   |                                         ^^^^^^^ invalid suffix `suffix`
-   |
-   = help: the suffix must be one of the numeric types (`u32`, `isize`, `f32`, etc.)
-
-error: aborting due to 21 previous errors
+error: aborting due to 20 previous errors