[gn build] Port f1ee047

Author: pcc

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

@@ -143,6 +143,7 @@ static_library("CodeGen") {
     "Targets/WebAssembly.cpp",
     "Targets/X86.cpp",
     "Targets/XCore.cpp",
+    "TrapReasonBuilder.cpp",
     "VarBypassDetector.cpp",
   ]
 }