[gn build] Port 056d2c1

Author: llvmgnsyncbot

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

@@ -88,6 +88,7 @@ static_library("CodeGen") {
     "LatencyPriorityQueue.cpp",
     "LazyMachineBlockFrequencyInfo.cpp",
     "LexicalScopes.cpp",
+    "LibcallLoweringInfo.cpp",
     "LiveDebugValues/InstrRefBasedImpl.cpp",
     "LiveDebugValues/LiveDebugValues.cpp",
     "LiveDebugValues/VarLocBasedImpl.cpp",