Revert "[llvm-cov] Warn when -arch spec is missing/invalid for universal binary"

This reverts commit b81d4bf.

It's causing some bots to fail to build due to: "error: no matching
function for call to ‘__iterator_category".

Author: vedantk

llvm/include/llvm/ProfileData/Coverage/CoverageMapping.h

@@ -55,8 +55,7 @@ enum class coveragemap_error {
   unsupported_version,
   truncated,
   malformed,
-  decompression_failed,
-  invalid_or_missing_arch_specifier
+  decompression_failed
 };
 
 const std::error_category &coveragemap_category();

llvm/lib/ProfileData/Coverage/CoverageMapping.cpp

@@ -816,8 +816,6 @@ static std::string getCoverageMapErrString(coveragemap_error Err) {
     return "Malformed coverage data";
   case coveragemap_error::decompression_failed:
     return "Failed to decompress coverage data (zlib)";
-  case coveragemap_error::invalid_or_missing_arch_specifier:
-    return "`-arch` specifier is invalid or missing for universal binary";
   }
   llvm_unreachable("A value of coveragemap_error has no message.");
 }

llvm/lib/ProfileData/Coverage/CoverageMappingReader.cpp

@@ -950,18 +950,6 @@ loadBinaryFormat(std::unique_ptr<Binary> Bin, StringRef Arch) {
       BytesInAddress, Endian);
 }
 
-/// Determine whether \p Arch is invalid or empty, given \p Bin.
-static bool isArchSpecifierInvalidOrMissing(Binary *Bin, StringRef Arch) {
-  // If we have a universal binary and Arch doesn't identify any of its slices,
-  // it's user error.
-  if (auto *Universal = dyn_cast<MachOUniversalBinary>(Bin))
-    return none_of(Universal->objects(),
-                   [Arch](const MachOUniversalBinary::ObjectForArch &Obj) {
-                     return Obj.getArchFlagName() == Arch;
-                   });
-  return false;
-}
-
 Expected<std::vector<std::unique_ptr<BinaryCoverageReader>>>
 BinaryCoverageReader::create(
     MemoryBufferRef ObjectBuffer, StringRef Arch,
@@ -982,10 +970,6 @@ BinaryCoverageReader::create(
     return BinOrErr.takeError();
   std::unique_ptr<Binary> Bin = std::move(BinOrErr.get());
 
-  if (isArchSpecifierInvalidOrMissing(Bin.get(), Arch))
-    return make_error<CoverageMapError>(
-        coveragemap_error::invalid_or_missing_arch_specifier);
-
   // MachO universal binaries which contain archives need to be treated as
   // archives, not as regular binaries.
   if (auto *Universal = dyn_cast<MachOUniversalBinary>(Bin.get())) {

llvm/test/tools/llvm-cov/universal-binary.c

@@ -10,9 +10,8 @@ int main(int argc, const char *argv[]) {}
 // COMBINED: showTemplateInstantiations.cpp
 // COMBINED-NEXT: universal-binary.c
 
-// RUN: not llvm-cov show %S/Inputs/universal-binary -instr-profile %t.profdata -path-equivalence=/tmp,%S %s 2>&1 | FileCheck --check-prefix=WRONG-ARCH %s
 // RUN: not llvm-cov show %S/Inputs/universal-binary -instr-profile %t.profdata -path-equivalence=/tmp,%S %s -arch i386 2>&1 | FileCheck --check-prefix=WRONG-ARCH %s
-// WRONG-ARCH: Failed to load coverage: `-arch` specifier is invalid or missing for universal binary
+// WRONG-ARCH: Failed to load coverage
 
 // RUN: not llvm-cov show %S/Inputs/universal-binary -instr-profile %t.profdata -path-equivalence=/tmp,%S %s -arch definitly_a_made_up_architecture 2>&1 | FileCheck --check-prefix=MADE-UP-ARCH %s
 // MADE-UP-ARCH: Unknown architecture: definitly_a_made_up_architecture