Use clang instead of clang-cl for CMake projects

This will be a requirement for upcoming libobjc2 releases. libdispatch must still be built with clang-cl.

build.bat

@@ -87,8 +87,8 @@ where cmake
 if %errorlevel% neq 0 call :error_missing_command cmake, "Visual Studio or 'choco install cmake --installargs ADD_CMAKE_TO_PATH=System'"
 where ninja
 if %errorlevel% neq 0 call :error_missing_command ninja, "'choco install ninja'"
-where clang-cl
-if %errorlevel% neq 0 call :error_missing_command clang-cl, "Visual Studio or 'choco install llvm'"
+where clang
+if %errorlevel% neq 0 call :error_missing_command clang, "Visual Studio or 'choco install llvm'"
 call %BASH% 'true'
 if %errorlevel% neq 0 call :error_missing_command MSYS2, "'choco install msys2'"
 call %BASH% 'which make'

phases/11-libobjc2.bat

@@ -22,9 +22,7 @@ cmake .. %CMAKE_OPTIONS% ^
 
 echo.
 echo ### Building
-set CCC_OVERRIDE_OPTIONS=x-TC x-TP x/TC x/TP
 ninja || exit /b 1
-set CCC_OVERRIDE_OPTIONS=
 
 echo.
 echo ### Installing

phases/18-libdispatch.bat

@@ -23,13 +23,16 @@ echo.
 echo ### Running cmake
 :: CXX and linker flags below are to produce PDBs for release builds.
 :: BlocksRuntime parameters provided to use blocks runtime from libobjc2 with libdispatch-own-blocksruntime.patch.
+:: libdispatch only supports building with clang-cl frontend.
 cmake .. %CMAKE_OPTIONS% ^
   -D BUILD_SHARED_LIBS=YES ^
   -D INSTALL_PRIVATE_HEADERS=YES ^
   -D CMAKE_CXX_FLAGS_RELWITHDEBINFO="/Zi" ^
   -D CMAKE_SHARED_LINKER_FLAGS_RELWITHDEBINFO="/INCREMENTAL:NO /DEBUG /OPT:REF /OPT:ICF" ^
   -D BlocksRuntime_INCLUDE_DIR=%INSTALL_PREFIX%\include ^
   -D BlocksRuntime_LIBRARIES=%INSTALL_PREFIX%\lib\objc.lib ^
+  -D CMAKE_C_COMPILER=clang-cl ^
+  -D CMAKE_CXX_COMPILER=clang-cl ^
   || exit /b 1
 
 echo.

scripts/sdkenv.bat

@@ -36,26 +36,26 @@ if "%ARCH%" == "x86" (
   exit /b 1
 )
 
-:: compiler/linker flags
-:: - -m32/64 flags are required to ensure the right architecture is built and linked,
-::   and setting these via CFLAGS doesn't work because GNUstep Make ignores those,
-::   so we set them as part of the compiler instead
-:: - LLD linker is required for linking Objective C
-if not defined CC set CC=clang %MFLAG%
-if not defined CXX set CXX=clang++ %MFLAG%
-if not defined OBJCC set OBJCC=clang %MFLAG%
-if not defined OBJCXX set OBJCXX=clang++ %MFLAG%
+:: compiler flags: -m32/64 is required to ensure the right architecture is
+:: built and linked. Unfortunately GNUstep Make ignores those, so we also set
+:: them as part of the compiler.
+if not defined CFLAGS set CFLAGS=%MFLAG%
+if not defined CXXFLAGS set CXXFLAGS=%MFLAG%
+if not defined OBJCFLAGS set OBJCFLAGS=%MFLAG%
+if not defined OBJCXXFLAGS set OBJCXXFLAGS=%MFLAG%
+if not defined ASMFLAGS set ASMFLAGS=%MFLAG%
+if not defined CC set "CC=clang %MFLAG%"
+if not defined CXX set "CXX=clang++ %MFLAG%"
+if not defined OBJCC set "OBJCC=clang %MFLAG%"
+if not defined OBJCXX set "OBJCXX=clang++ %MFLAG%"
+
+:: LLD linker is required for linking Objective C
 set LDFLAGS=-fuse-ld=lld
 
 :: common CMake options
-:: - CMAKE_C(XX)_COMPILER_TARGET are required to ensure the right architecture is built and linked
 set CMAKE_BUILD_TYPE=%BUILD_TYPE%
 if "%BUILD_TYPE%" == "Release" set CMAKE_BUILD_TYPE=RelWithDebInfo
 set CMAKE_OPTIONS=^
   -G Ninja ^
   -D CMAKE_BUILD_TYPE=%CMAKE_BUILD_TYPE% ^
   -D CMAKE_INSTALL_PREFIX="%INSTALL_PREFIX%" ^
-  -D CMAKE_C_COMPILER=clang-cl ^
-  -D CMAKE_CXX_COMPILER=clang-cl ^
-  -D CMAKE_C_COMPILER_TARGET=%TARGET% ^
-  -D CMAKE_CXX_COMPILER_TARGET=%TARGET% ^