[gn build] Port d4cdb51

Author: llvmgnsyncbot

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

@@ -61,6 +61,7 @@ static_library("LLVMWebAssemblyCodeGen") {
     "WebAssemblyOptimizeLiveIntervals.cpp",
     "WebAssemblyOptimizeReturned.cpp",
     "WebAssemblyPeephole.cpp",
+    "WebAssemblyRefTypeMem2Local.cpp",
     "WebAssemblyRegColoring.cpp",
     "WebAssemblyRegNumbering.cpp",
     "WebAssemblyRegStackify.cpp",