coverage: Re-land "Enlarge empty spans during MIR instrumentation"

This allows us to assume that coverage spans will only be discarded during
codegen in very unusual situations.

4 files changed, 9 insertions, 39 deletions

diff --git a/tests/coverage/async_closure.cov-map b/tests/coverage/async_closure.cov-map
index 9f8dc8d6cbb..53128dd7a48 100644
--- a/tests/coverage/async_closure.cov-map
+++ b/tests/coverage/async_closure.cov-map
@@ -37,32 +37,29 @@ Number of file 0 mappings: 8
 Highest counter ID seen: c0
 
 Function name: async_closure::main::{closure#0}
-Raw bytes (14): 0x[01, 01, 00, 02, 01, 0b, 22, 00, 23, 01, 00, 23, 00, 24]
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 0b, 22, 00, 24]
 Number of files: 1
 - file 0 => $DIR/async_closure.rs
 Number of expressions: 0
-Number of file 0 mappings: 2
-- Code(Counter(0)) at (prev + 11, 34) to (start + 0, 35)
-- Code(Counter(0)) at (prev + 0, 35) to (start + 0, 36)
+Number of file 0 mappings: 1
+- Code(Counter(0)) at (prev + 11, 34) to (start + 0, 36)
 Highest counter ID seen: c0
 
 Function name: async_closure::main::{closure#0}
-Raw bytes (14): 0x[01, 01, 00, 02, 01, 0b, 22, 00, 23, 01, 00, 23, 00, 24]
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 0b, 22, 00, 24]
 Number of files: 1
 - file 0 => $DIR/async_closure.rs
 Number of expressions: 0
-Number of file 0 mappings: 2
-- Code(Counter(0)) at (prev + 11, 34) to (start + 0, 35)
-- Code(Counter(0)) at (prev + 0, 35) to (start + 0, 36)
+Number of file 0 mappings: 1
+- Code(Counter(0)) at (prev + 11, 34) to (start + 0, 36)
 Highest counter ID seen: c0
 
 Function name: async_closure::main::{closure#0}::{closure#0}::<i16>
-Raw bytes (14): 0x[01, 01, 00, 02, 01, 0b, 22, 00, 23, 01, 00, 23, 00, 24]
+Raw bytes (9): 0x[01, 01, 00, 01, 01, 0b, 22, 00, 24]
 Number of files: 1
 - file 0 => $DIR/async_closure.rs
 Number of expressions: 0
-Number of file 0 mappings: 2
-- Code(Counter(0)) at (prev + 11, 34) to (start + 0, 35)
-- Code(Counter(0)) at (prev + 0, 35) to (start + 0, 36)
+Number of file 0 mappings: 1
+- Code(Counter(0)) at (prev + 11, 34) to (start + 0, 36)
 Highest counter ID seen: c0
 
diff --git a/tests/coverage/try-in-macro.attr.cov-map b/tests/coverage/try-in-macro.attr.cov-map
index 7111e89637c..1b6c97cf145 100644
--- a/tests/coverage/try-in-macro.attr.cov-map
+++ b/tests/coverage/try-in-macro.attr.cov-map
@@ -1,12 +1,3 @@
-Function name: <try_in_macro::MyEnum as try_in_macro::Arbitrary>::try_size_hint
-Raw bytes (9): 0x[01, 01, 00, 01, 00, 1e, 2a, 00, 2b]
-Number of files: 1
-- file 0 => $DIR/try-in-macro.rs
-Number of expressions: 0
-Number of file 0 mappings: 1
-- Code(Zero) at (prev + 30, 42) to (start + 0, 43)
-Highest counter ID seen: (none)
-
 Function name: try_in_macro::main
 Raw bytes (19): 0x[01, 01, 00, 03, 01, 29, 01, 00, 0a, 01, 01, 05, 00, 1a, 01, 01, 01, 00, 02]
 Number of files: 1
diff --git a/tests/coverage/try-in-macro.bang.cov-map b/tests/coverage/try-in-macro.bang.cov-map
index 80bd91a993c..1b6c97cf145 100644
--- a/tests/coverage/try-in-macro.bang.cov-map
+++ b/tests/coverage/try-in-macro.bang.cov-map
@@ -1,12 +1,3 @@
-Function name: <try_in_macro::MyEnum as try_in_macro::Arbitrary>::try_size_hint
-Raw bytes (9): 0x[01, 01, 00, 01, 00, 23, 1c, 00, 1d]
-Number of files: 1
-- file 0 => $DIR/try-in-macro.rs
-Number of expressions: 0
-Number of file 0 mappings: 1
-- Code(Zero) at (prev + 35, 28) to (start + 0, 29)
-Highest counter ID seen: (none)
-
 Function name: try_in_macro::main
 Raw bytes (19): 0x[01, 01, 00, 03, 01, 29, 01, 00, 0a, 01, 01, 05, 00, 1a, 01, 01, 01, 00, 02]
 Number of files: 1
diff --git a/tests/coverage/try-in-macro.derive.cov-map b/tests/coverage/try-in-macro.derive.cov-map
index 6646b6693ba..1b6c97cf145 100644
--- a/tests/coverage/try-in-macro.derive.cov-map
+++ b/tests/coverage/try-in-macro.derive.cov-map
@@ -1,12 +1,3 @@
-Function name: <try_in_macro::MyEnum as try_in_macro::Arbitrary>::try_size_hint
-Raw bytes (9): 0x[01, 01, 00, 01, 00, 26, 38, 00, 39]
-Number of files: 1
-- file 0 => $DIR/try-in-macro.rs
-Number of expressions: 0
-Number of file 0 mappings: 1
-- Code(Zero) at (prev + 38, 56) to (start + 0, 57)
-Highest counter ID seen: (none)
-
 Function name: try_in_macro::main
 Raw bytes (19): 0x[01, 01, 00, 03, 01, 29, 01, 00, 0a, 01, 01, 05, 00, 1a, 01, 01, 01, 00, 02]
 Number of files: 1