IR: Replace the "Linker Options" module flag with "llvm.linker.options" named metadata.

The new metadata is easier to manipulate than module flags.

Differential Revision: https://reviews.llvm.org/D31349

llvm-svn: 305227

llvm/lib/Bitcode/Reader/BitcodeReader.cpp

@@ -2608,6 +2608,16 @@ Error BitcodeReader::materializeMetadata() {
     if (Error Err = MDLoader->parseModuleMetadata())
       return Err;
   }
+
+  // Upgrade "Linker Options" module flag to "llvm.linker.options" module-level
+  // metadata.
+  if (Metadata *Val = TheModule->getModuleFlag("Linker Options")) {
+    NamedMDNode *LinkerOpts =
+        TheModule->getOrInsertNamedMetadata("llvm.linker.options");
+    for (const MDOperand &MDOptions : cast<MDNode>(Val)->operands())
+      LinkerOpts->addOperand(cast<MDNode>(MDOptions));
+  }
+
   DeferredMetadataInfo.clear();
   return Error::success();
 }