[gn build] Port 4b5e7fa

Author: llvmgnsyncbot

llvm/utils/gn/secondary/clang/lib/AST/BUILD.gn

@@ -62,6 +62,7 @@ static_library("AST") {
     "AttrDocTable.cpp",
     "AttrImpl.cpp",
     "Availability.cpp",
+    "ByteCode/BitcastBuffer.cpp",
     "ByteCode/ByteCodeEmitter.cpp",
     "ByteCode/Compiler.cpp",
     "ByteCode/Context.cpp",

llvm/utils/gn/secondary/clang/unittests/AST/ByteCode/BUILD.gn

@@ -10,6 +10,7 @@ unittest("InterpTests") {
     "//clang/lib/Tooling",
   ]
   sources = [
+    "BitcastBuffer.cpp",
     "Descriptor.cpp",
     "toAPValue.cpp",
   ]