Update build-windows-toolchain.bat

Checkout tags even though it carries ~20% build overhead as swift-experimental-string-processing requires that.

Author: compnerd

utils/build-windows-toolchain.bat

@@ -201,6 +201,7 @@ cmake ^
   -D PYTHON_HOME=%PYTHON_HOME% ^
   -D PYTHON_EXECUTABLE=%PYTHON_HOME%\python.exe ^
   -D SWIFT_PATH_TO_LIBDISPATCH_SOURCE="%SourceRoot%\swift-corelibs-libdispatch" ^
+  -D EXPERIMENTAL_STRING_PROCESSING_SOURCE_DIR=%SourceRoot%\swift-experimental-string-processing ^
   -D SWIFT_WINDOWS_x86_64_ICU_UC_INCLUDE="%BuildRoot%\Library\icu-67.1\include\unicode" ^
   -D SWIFT_WINDOWS_x86_64_ICU_UC="%BuildRoot%\Library\icu-67.1\lib64\icuuc.lib" ^
   -D SWIFT_WINDOWS_x86_64_ICU_I18N_INCLUDE="%BuildRoot%\Library\icu-67.1\include" ^
@@ -231,6 +232,7 @@ cmake ^
   -D LLVM_DIR=%BuildRoot%\1\lib\cmake\llvm ^
   -D SWIFT_NATIVE_SWIFT_TOOLS_PATH=%BuildRoot%\1\bin ^
   -D SWIFT_PATH_TO_LIBDISPATCH_SOURCE=%SourceRoot%\swift-corelibs-libdispatch ^
+  -D EXPERIMENTAL_STRING_PROCESSING_SOURCE_DIR=%SourceRoot%\swift-experimental-string-processing ^
   -D SWIFT_WINDOWS_x86_64_ICU_UC_INCLUDE="%BuildRoot%\Library\icu-67.1\include\unicode" ^
   -D SWIFT_WINDOWS_x86_64_ICU_UC="%BuildRoot%\Library\icu-67.1\lib64\icuuc.lib" ^
   -D SWIFT_WINDOWS_x86_64_ICU_I18N_INCLUDE="%BuildRoot%\Library\icu-67.1\include" ^
@@ -815,7 +817,7 @@ set "args=%args% --skip-repository swift-integration-tests"
 set "args=%args% --skip-repository swift-stress-tester"
 set "args=%args% --skip-repository swift-xcode-playground-support"
 
-call "%SourceRoot%\swift\utils\update-checkout.cmd" %args% --clone --skip-tags --skip-history --github-comment "%ghprbCommentBody%"
+call "%SourceRoot%\swift\utils\update-checkout.cmd" %args% --clone --skip-history --github-comment "%ghprbCommentBody%"
 
 goto :eof
 endlocal