[gn build] Port 33872f1

Author: llvmgnsyncbot

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

@@ -60,6 +60,7 @@ static_library("MC") {
     "MCSectionCOFF.cpp",
     "MCSectionDXContainer.cpp",
     "MCSectionELF.cpp",
+    "MCSectionGOFF.cpp",
     "MCSectionMachO.cpp",
     "MCSectionWasm.cpp",
     "MCSectionXCOFF.cpp",