Make source-based code coverage compatible with MIR inlining When codegenning code coverage use the instance that coverage data was originally generated for, to ensure basic level of compatibility with MIR inlining. Fixes #83061
-Ctarget-cpu=native
rustc_codegen_{llvm,ssa}
-Zrun-dsymutil
-Csplit-debuginfo
fewer_names
uncached_llvm_type