libdispatch: enable building for x86

This is now supported due to our patch for using our own BlocksRuntime.

README.md

@@ -95,7 +95,6 @@ As support for using GNUstep with the MSVC ABI has only been recently added, and
 
 Following is a list of some of the open items.
 
-- [ ] Add support for building libdispatch for x86 (currently blocked by [libdispatch build issue](https://bugs.swift.org/browse/SR-14314))
 - [ ] Figure out building Objective-C code in Visual Studio
 - [ ] Fix tests in GNUstep Base
 - [ ] Provide pre-built binaries

patches/libdispatch-fix-stdcall.patch

@@ -0,0 +1,13 @@
+diff --git a/src/shims/tsd.h b/src/shims/tsd.h
+index 446c4d7..f8b5ec9 100644
+--- a/src/shims/tsd.h
++++ b/src/shims/tsd.h
+@@ -158,7 +158,7 @@ struct dispatch_tsd {
+ extern _Thread_local struct dispatch_tsd __dispatch_tsd;
+
+ extern void libdispatch_tsd_init(void);
+-extern void _libdispatch_tsd_cleanup(void *ctx);
++extern void DISPATCH_TSD_DTOR_CC _libdispatch_tsd_cleanup(void *ctx);
+
+ DISPATCH_ALWAYS_INLINE
+ static inline struct dispatch_tsd *

phases/18-libdispatch.bat

@@ -8,12 +8,6 @@ set TAG=
 :: load environment and prepare project
 call "%~dp0\..\scripts\common.bat" prepare_project || exit /b 1
 
-if "%ARCH%" == "x86" (
-  echo Skipping libdispatch for x86
-  echo Blocked on issue: https://bugs.swift.org/browse/SR-14314
-  exit /b 0
-)
-
 set BUILD_DIR="%SRCROOT%\%PROJECT%\build-%ARCH%-%BUILD_TYPE%"
 if exist "%BUILD_DIR%" (rmdir /S /Q "%BUILD_DIR%" || exit /b 1)
 mkdir "%BUILD_DIR%" || exit /b 1