[gn build] Port c1c68ba

Author: llvmgnsyncbot

llvm/utils/gn/secondary/llvm/unittests/Target/AArch64/BUILD.gn

@@ -17,6 +17,7 @@ unittest("AArch64Tests") {
   include_dirs = [ "//llvm/lib/Target/AArch64" ]
   sources = [
     "AArch64InstPrinterTest.cpp",
+    "AArch64RegisterInfoTest.cpp",
     "AArch64SVESchedPseudoTest.cpp",
     "AddressingModes.cpp",
     "DecomposeStackOffsetTest.cpp",