oneapi: disable use of libirc when building C++

When building with C++ the icx compiler will try to utilize optimized
versions of memset/memcpy that are provided as part of libirc.  However
libirc also has dependencies on things likes getenv/setenv, etc that
are expect in a linux host environment.  So disable use of libirc
via compiler flag -no-intel-lib=libirc.

Signed-off-by: Kumar Gala <[email protected]>

Author: galak

cmake/compiler/icx/target.cmake

@@ -40,9 +40,9 @@ foreach(isystem_include_dir ${NOSTDINC})
 endforeach()
 
 if(CONFIG_64BIT)
-  string(APPEND TOOLCHAIN_C_FLAGS "-m64")
+  list(APPEND TOOLCHAIN_C_FLAGS "-m64")
 else()
-  string(APPEND TOOLCHAIN_C_FLAGS "-m32")
+  list(APPEND TOOLCHAIN_C_FLAGS "-m32")
 endif()
 
 
@@ -67,3 +67,7 @@ string(REPLACE ";" " " CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS}")
 macro(toolchain_cc_nostdinc)
     zephyr_compile_options( -nostdinc)
 endmacro()
+
+if(CONFIG_CPP)
+  list(APPEND TOOLCHAIN_C_FLAGS "-no-intel-lib=libirc")
+endif()