Unrolled build for rust-lang#118941

Rollup merge of rust-lang#118941 - krasimirgg:llvm-cov, r=nikic

llvm-wrapper: adapt for LLVM API changes

Adapt for llvm/llvm-project@8ecbb04.

r? `@nikic`
`@rustbot` label: +llvm-main

Author: rust-timer

compiler/rustc_llvm/llvm-wrapper/CoverageMappingWrapper.cpp

@@ -139,6 +139,9 @@ extern "C" void LLVMRustCoverageWriteMappingToBuffer(
            RustMappingRegions, NumMappingRegions)) {
     MappingRegions.emplace_back(
         fromRust(Region.Count), fromRust(Region.FalseCount),
+#if LLVM_VERSION_GE(18, 0)
+        coverage::CounterMappingRegion::MCDCParameters{},
+#endif
         Region.FileID, Region.ExpandedFileID,
         Region.LineStart, Region.ColumnStart, Region.LineEnd, Region.ColumnEnd,
         fromRust(Region.Kind));