[gn build] Port 8d5dead

Author: llvmgnsyncbot

llvm/utils/gn/secondary/lldb/source/Plugins/Process/Utility/BUILD.gn

@@ -30,6 +30,7 @@ static_library("Utility") {
     "MemoryTagManagerAArch64MTE.cpp",
     "NativeProcessSoftwareSingleStep.cpp",
     "NativeRegisterContextDBReg.cpp",
+    "NativeRegisterContextDBReg_arm.cpp",
     "NativeRegisterContextDBReg_arm64.cpp",
     "NativeRegisterContextDBReg_loongarch.cpp",
     "NativeRegisterContextDBReg_x86.cpp",