[gn build] Port b861b12

Author: llvmgnsyncbot

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

@@ -15,5 +15,6 @@ static_library("TextAPI") {
     "Target.cpp",
     "TextStub.cpp",
     "TextStubCommon.cpp",
+    "TextStubV5.cpp",
   ]
 }

llvm/utils/gn/secondary/llvm/unittests/TextAPI/BUILD.gn

@@ -10,5 +10,6 @@ unittest("TextAPITests") {
     "TextStubV2Tests.cpp",
     "TextStubV3Tests.cpp",
     "TextStubV4Tests.cpp",
+    "TextStubV5Tests.cpp",
   ]
 }