f146b36: shaderCompiler: use clang for both x86_64 and arm64 under windows

Author: NicSavichev

prog/tools/ShaderCompiler2/jamfile-common

@@ -1,6 +1,5 @@
 PlatformArch_windows ?= x86_64 ;
-PlatformSpec_windows_x86_64 ?= clang ;
-PlatformSpec_windows_arm64 ?= vc17 ; # clang 15.0.7 crashes with dag_shaderModelVersion.h when building arm64
+PlatformSpec_windows ?= clang ;
 include $(Root)/prog/_jBuild/defPlatform.jam ;
 if ! $(Location) { Exit Location must be defined before including jamfile-common ; }