[gn build] Port 128214f

Author: llvmgnsyncbot

llvm/utils/gn/secondary/llvm/tools/llvm-remarkutil/BUILD.gn

@@ -13,6 +13,7 @@ executable("llvm-remarkutil") {
     "RemarkFilter.cpp",
     "RemarkInstructionMix.cpp",
     "RemarkSizeDiff.cpp",
+    "RemarkSummary.cpp",
     "RemarkUtil.cpp",
     "RemarkUtilHelpers.cpp",
     "RemarkUtilRegistry.cpp",