Merge pull request #6424 from vedantk/re-reenable-coverage-smoke

[Coverage] Fix UB in use of the CoverageMappingWriter API

Author: vedantk

lib/IRGen/GenCoverage.cpp

@@ -97,8 +97,9 @@ void IRGenModule::emitCoverageMapping() {
           MR.Counter, /*FileID=*/0, MR.StartLine, MR.StartCol, MR.EndLine,
           MR.EndCol));
     // Append each function's regions into the encoded buffer.
-    llvm::coverage::CoverageMappingWriter W({FileID}, M.getExpressions(),
-                                            Regions);
+    ArrayRef<unsigned> VirtualFileMapping(FileID);
+    llvm::coverage::CoverageMappingWriter W(VirtualFileMapping,
+                                            M.getExpressions(), Regions);
     W.write(OS);
 
     std::string NameValue = llvm::getPGOFuncName(

test/SILGen/coverage_smoke.swift

@@ -1,4 +1,3 @@
-// REQUIRES: rdar://29591622
 // RUN: rm -rf %t && mkdir -p %t
 // RUN: %target-build-swift %s -profile-generate -profile-coverage-mapping -Xfrontend -disable-incremental-llvm-codegen -o %t/main
 // RUN: env LLVM_PROFILE_FILE=%t/default.profraw %target-run %t/main