[gn build] Port b1ebfac

Author: llvmgnsyncbot

llvm/utils/gn/secondary/llvm/lib/Support/BUILD.gn

@@ -33,6 +33,7 @@ static_library("Support") {
     "Windows",
   ]
   sources = [
+    "AArch64AttributeParser.cpp",
     "AArch64BuildAttributes.cpp",
     "ABIBreak.cpp",
     "AMDGPUMetadata.cpp",
@@ -77,7 +78,8 @@ static_library("Support") {
     "DeltaTree.cpp",
     "DivisionByConstantInfo.cpp",
     "DynamicAPInt.cpp",
-    "ELFAttributeParser.cpp",
+    "ELFAttrParserCompact.cpp",
+    "ELFAttrParserExtended.cpp",
     "ELFAttributes.cpp",
     "Error.cpp",
     "ErrorHandling.cpp",