[gn build] Port cb508a0

Author: llvmgnsyncbot

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

@@ -50,6 +50,7 @@ static_library("LLVMHexagonCodeGen") {
     "HexagonCommonGEP.cpp",
     "HexagonConstExtenders.cpp",
     "HexagonConstPropagation.cpp",
+    "HexagonCopyHoisting.cpp",
     "HexagonCopyToCombine.cpp",
     "HexagonEarlyIfConv.cpp",
     "HexagonExpandCondsets.cpp",