Update Windows Build Scripts

Author: CodaFi

utils/build-windows.bat

@@ -282,6 +282,7 @@ 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^
     -S "%source_root%\swift" %exitOnError%
 
 cmake --build "%build_root%\swift" %exitOnError%

utils/swift_build_support/swift_build_support/build_script_invocation.py

@@ -248,7 +248,7 @@ def convert_to_impl_arguments(self):
         swift_syntax_src = os.path.join(self.workspace.source_root,
                                         "swift-syntax")
         args.extra_cmake_options.append(
-            'SWIFT_PATH_TO_SWIFT_SYNTAX_SOURCE:PATH={}'.format(swift_syntax_src))
+            '-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