Update Windows Build Scripts

Author: CodaFi

utils/build-windows.bat

@@ -122,7 +122,6 @@ git -C "%source_root%\swift" checkout-index --force --all
 @set "skip_repositories_arg=%skip_repositories_arg% --skip-repository swift-integration-tests"
 @set "skip_repositories_arg=%skip_repositories_arg% --skip-repository swiftpm"
 @set "skip_repositories_arg=%skip_repositories_arg% --skip-repository swift-stress-tester"
-@set "skip_repositories_arg=%skip_repositories_arg% --skip-repository swift-syntax"
 @set "skip_repositories_arg=%skip_repositories_arg% --skip-repository swift-tools-support-core"
 @set "skip_repositories_arg=%skip_repositories_arg% --skip-repository swift-xcode-playground-support"
 @set "skip_repositories_arg=%skip_repositories_arg% --skip-repository tensorflow-swift-apis"
@@ -282,6 +281,8 @@ cmake^
     -DCMAKE_EXE_LINKER_FLAGS:STRING=/INCREMENTAL:NO^
     -DCMAKE_SHARED_LINKER_FLAGS:STRING=/INCREMENTAL:NO^
     -DSWIFT_LIT_ARGS="--time-tests"^
+    -DSWIFT_PATH_TO_SWIFT_SYNTAX_SOURCE:PATH=%source_root%\swift-syntax^
+    -DSWIFT_PATH_TO_SWIFT_SYNTAX_SOURCE:PATH=%source_root%\swift-syntax^
     -S "%source_root%\swift" %exitOnError%
 
 cmake --build "%build_root%\swift" %exitOnError%

utils/swift_build_support/swift_build_support/build_script_invocation.py

@@ -245,6 +245,11 @@ def convert_to_impl_arguments(self):
             args.extra_cmake_options.append(
                 '-DSWIFT_BACK_DEPLOY_CONCURRENCY:BOOL=TRUE')
 
+        swift_syntax_src = os.path.join(self.workspace.source_root,
+                                        "swift-syntax")
+        args.extra_cmake_options.append(
+            '-DSWIFT_PATH_TO_SWIFT_SYNTAX_SOURCE:PATH={}'.format(swift_syntax_src))
+
         # Then add subproject install flags that either skip building them /or/
         # if we are going to build them and install_all is set, we also install
         # them.