coverage: Revert "unused local file IDs" due to empty function names

This reverts commit 3b22c21dd8c30f499051fe7a758ca0e5d81eb638, reversing
changes made to 5f292eea6d63abbd26f1e6e00a0b8cf21d828d7d.

3 files changed, 12 insertions, 38 deletions

diff --git a/tests/coverage/async_closure.cov-map b/tests/coverage/async_closure.cov-map
index 53128dd7a48..9f8dc8d6cbb 100644
--- a/tests/coverage/async_closure.cov-map
+++ b/tests/coverage/async_closure.cov-map
@@ -37,29 +37,32 @@ Number of file 0 mappings: 8
 Highest counter ID seen: c0
 
 Function name: async_closure::main::{closure#0}
-Raw bytes (9): 0x[01, 01, 00, 01, 01, 0b, 22, 00, 24]
+Raw bytes (14): 0x[01, 01, 00, 02, 01, 0b, 22, 00, 23, 01, 00, 23, 00, 24]
 Number of files: 1
 - file 0 => $DIR/async_closure.rs
 Number of expressions: 0
-Number of file 0 mappings: 1
-- Code(Counter(0)) at (prev + 11, 34) to (start + 0, 36)
+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)
 Highest counter ID seen: c0
 
 Function name: async_closure::main::{closure#0}
-Raw bytes (9): 0x[01, 01, 00, 01, 01, 0b, 22, 00, 24]
+Raw bytes (14): 0x[01, 01, 00, 02, 01, 0b, 22, 00, 23, 01, 00, 23, 00, 24]
 Number of files: 1
 - file 0 => $DIR/async_closure.rs
 Number of expressions: 0
-Number of file 0 mappings: 1
-- Code(Counter(0)) at (prev + 11, 34) to (start + 0, 36)
+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)
 Highest counter ID seen: c0
 
 Function name: async_closure::main::{closure#0}::{closure#0}::<i16>
-Raw bytes (9): 0x[01, 01, 00, 01, 01, 0b, 22, 00, 24]
+Raw bytes (14): 0x[01, 01, 00, 02, 01, 0b, 22, 00, 23, 01, 00, 23, 00, 24]
 Number of files: 1
 - file 0 => $DIR/async_closure.rs
 Number of expressions: 0
-Number of file 0 mappings: 1
-- Code(Counter(0)) at (prev + 11, 34) to (start + 0, 36)
+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)
 Highest counter ID seen: c0
 
diff --git a/tests/coverage/unused-local-file.coverage b/tests/coverage/unused-local-file.coverage
deleted file mode 100644
index 8f5a32f6d70..00000000000
--- a/tests/coverage/unused-local-file.coverage
+++ /dev/null
@@ -1,7 +0,0 @@
-   LL|       |//@ edition: 2021
-   LL|       |
-   LL|       |// Force this function to be generated in its home crate, so that it ends up
-   LL|       |// with normal coverage metadata.
-   LL|       |#[inline(never)]
-   LL|      1|pub fn external_function() {}
-
diff --git a/tests/coverage/unused-local-file.rs b/tests/coverage/unused-local-file.rs
deleted file mode 100644
index cf43c62d703..00000000000
--- a/tests/coverage/unused-local-file.rs
+++ /dev/null
@@ -1,22 +0,0 @@
-//! If we give LLVM a local file table for a function, but some of the entries
-//! in that table have no associated mapping regions, then an assertion failure
-//! will occur in LLVM. We therefore need to detect and skip any function that
-//! would trigger that assertion.
-//!
-//! To test that this case is handled, even before adding code that could allow
-//! it to happen organically (for expansion region support), we use a special
-//! testing-only flag to force it to occur.
-
-//@ edition: 2024
-//@ compile-flags: -Zcoverage-options=inject-unused-local-file
-
-// The `llvm-cov` tool will complain if the test binary ends up having no
-// coverage metadata at all. To prevent that, we also link to instrumented
-// code in an auxiliary crate that doesn't have the special flag set.
-
-//@ aux-build: discard_all_helper.rs
-extern crate discard_all_helper;
-
-fn main() {
-    discard_all_helper::external_function();
-}