[gn build] Port 63c1be7

Author: llvmgnsyncbot

llvm/utils/gn/secondary/llvm/lib/Transforms/IPO/BUILD.gn

@@ -35,6 +35,7 @@ static_library("IPO") {
     "EmbedBitcodePass.cpp",
     "ExpandVariadics.cpp",
     "ExtractGV.cpp",
+    "FatLTOCleanup.cpp",
     "ForceFunctionAttrs.cpp",
     "FunctionAttrs.cpp",
     "FunctionImport.cpp",