Rollup merge of #79958 - richkadel:llvm-coverage-counters-2.2.0, r=tmandry

Fixes reported bugs in Rust Coverage

Fixes: #79569

Fixes: #79566
Fixes: #79565

For the first issue (#79569), I got hit a `debug_assert!()` before
encountering the reported error message (because I have `debug = true`
enabled in my config.toml).

The assertion showed me that some `SwitchInt`s can have more than one
target pointing to the same `BasicBlock`.

I had thought that was invalid, but since it seems to be possible, I'm
allowing this now.

I added a new test for this.

----

In the last two cases above, both tests (intentionally) fail to compile,
but the `InstrumentCoverage` pass is invoked anyway.

The MIR starts with an `Unreachable` `BasicBlock`, which I hadn't
encountered before. (I had assumed the `InstrumentCoverage` pass
would only be invoked with MIRs from successful compilations.)

I don't have test infrastructure set up to test coverage on files that
fail to compile, so I didn't add a new test.

r? `@tmandry`
FYI: `@wesleywiser`

1 files changed, 1 insertions, 1 deletions

diff --git a/compiler/rustc_interface/src/tests.rs b/compiler/rustc_interface/src/tests.rs
index 2273266a3ff..3e94f163773 100644
--- a/compiler/rustc_interface/src/tests.rs
+++ b/compiler/rustc_interface/src/tests.rs
@@ -587,7 +587,7 @@ fn test_debugging_options_tracking_hash() {
     tracked!(share_generics, Some(true));
     tracked!(show_span, Some(String::from("abc")));
     tracked!(src_hash_algorithm, Some(SourceFileHashAlgorithm::Sha1));
-    tracked!(symbol_mangling_version, SymbolManglingVersion::V0);
+    tracked!(symbol_mangling_version, Some(SymbolManglingVersion::V0));
     tracked!(teach, true);
     tracked!(thinlto, Some(true));
     tracked!(tune_cpu, Some(String::from("abc")));