Fix SSE4.1, RDSEED requirement for clang-cl builds

A misunderstanding seems to have caused several files to be compiled
with extra runtime arch options.

We need to disable multi-target functions though, because it doesn't
work with clang-cl headers.

Task-number: QTBUG-88081
Task-number: QTBUG-88434
Pick-to: 6.2
Change-Id: Ic5829540f9007428c80f9a7bd46af35540745ccd
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

src/corelib/CMakeLists.txt

@@ -269,26 +269,6 @@ qt_internal_add_module(Core
     # special case end
 )
 
-if (MSVC AND CLANG)
-    foreach(subarch sse4_1 rdrnd rdseed)
-        if (TEST_subarch_${subarch})
-            qt_internal_add_simd_part(Core SIMD ${subarch}
-                SOURCES
-                    global/qsimd.cpp
-            )
-        endif()
-    endforeach()
-
-    foreach(subarch sse4_1 aesni)
-        if (TEST_subarch_${subarch})
-            qt_internal_add_simd_part(Core SIMD ${subarch}
-                SOURCES
-                    tools/qhash.cpp
-            )
-        endif()
-    endforeach()
-endif()
-
 qt_update_ignore_pch_source(Core kernel/qmetatype.cpp )
 
 # special case begin

src/corelib/global/qsimd_p.h

@@ -163,7 +163,11 @@
 #    define __MIPS_DSPR2__
 #  endif
 #elif defined(Q_PROCESSOR_X86) && defined(QT_COMPILER_SUPPORTS_SIMD_ALWAYS)
-#  define QT_COMPILER_SUPPORTS_HERE(x)    ((__ ## x ## __) || QT_COMPILER_SUPPORTS(x))
+#  if defined(Q_CC_CLANG) && defined(Q_CC_MSVC)
+#    define QT_COMPILER_SUPPORTS_HERE(x)    (__ ## x ## __)
+#  else
+#    define QT_COMPILER_SUPPORTS_HERE(x)    ((__ ## x ## __) || QT_COMPILER_SUPPORTS(x))
+#  endif
 #  if defined(Q_CC_GNU) && !defined(Q_CC_INTEL)
      /* GCC requires attributes for a function */
 #    define QT_FUNCTION_TARGET(x)  __attribute__((__target__(QT_FUNCTION_TARGET_STRING_ ## x)))

src/gui/CMakeLists.txt

@@ -577,15 +577,6 @@ if(NOT ANDROID)
         )
     endif()
 
-    if (MSVC AND CLANG AND TEST_subarch_sse4_1)
-        qt_internal_add_simd_part(Gui SIMD sse4_1
-            SOURCES
-                painting/qdrawhelper.cpp
-                painting/qdrawhelper_sse2.cpp
-                painting/qdrawhelper_ssse3.cpp
-        )
-    endif()
-
     qt_internal_add_simd_part(Gui SIMD ssse3
         SOURCES
             image/qimage_ssse3.cpp