[CMake] Disable precompiled headers for ccache builds on Windows

Signed-off-by: Kajetan Puchalski <kajetan.puchalski@arm.com>

Author: mrkajetanp

llvm/CMakeLists.txt

@@ -286,6 +286,9 @@ if(LLVM_CCACHE_BUILD)
       endif()
       set_property(GLOBAL PROPERTY RULE_LAUNCH_COMPILE ${CCACHE_PROGRAM})
     else()
+      # Until a way to reliably configure ccache on Windows is found,
+      # disable precompiled headers for Windows + ccache builds
+      set(CMAKE_DISABLE_PRECOMPILE_HEADERS "ON")
       if(LLVM_CCACHE_MAXSIZE OR LLVM_CCACHE_DIR OR
          NOT LLVM_CCACHE_PARAMS MATCHES "CCACHE_CPP2=yes CCACHE_HASHDIR=yes CCACHE_SLOPPINESS=pch_defines,time_macros")
         message(FATAL_ERROR "Ccache configuration through CMake is not supported on Windows. Please use environment variables.")