[gn build] Port 78e636b

Author: llvmgnsyncbot

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

@@ -52,6 +52,7 @@ static_library("Basic") {
     "Diagnostic.cpp",
     "DiagnosticIDs.cpp",
     "DiagnosticOptions.cpp",
+    "ExpressionTraits.cpp",
     "FileManager.cpp",
     "FileSystemStatCache.cpp",
     "FixedPoint.cpp",
@@ -94,6 +95,7 @@ static_library("Basic") {
     "Targets/X86.cpp",
     "Targets/XCore.cpp",
     "TokenKinds.cpp",
+    "TypeTraits.cpp",
     "Version.cpp",
     "Warnings.cpp",
     "XRayInstr.cpp",