[gn build] Port 0ee037b

Author: llvmgnsyncbot

llvm/utils/gn/secondary/llvm/lib/Target/AMDGPU/BUILD.gn

@@ -181,6 +181,8 @@ static_library("LLVMAMDGPUCodeGen") {
     "AMDGPUPromoteKernelArguments.cpp",
     "AMDGPURegBankCombiner.cpp",
     "AMDGPURegBankLegalize.cpp",
+    "AMDGPURegBankLegalizeHelper.cpp",
+    "AMDGPURegBankLegalizeRules.cpp",
     "AMDGPURegBankSelect.cpp",
     "AMDGPURegisterBankInfo.cpp",
     "AMDGPURemoveIncompatibleFunctions.cpp",