cmake: compiler: Add framework for disabling C++ standard includes

[stephanosio]

This commit adds a new C++ compiler property `nostdincxx` which
specifies the C++ compiler flag for excluding the C++ standard library
include directory from the include paths.

Signed-off-by: Stephanos Ioannidis <[email protected]>

Fixes #36644.

[stephanosio]

@evgeniy-paltsev @abrodkin Does ARC MWDT have something like -nostdinc++ from GCC? If so, we should specify the nostdincxx property for the MWDT as well.

[cfriedt]

LGTM

[cfriedt]

@tejlmand - can you take a look?

[cfriedt]

@nashif - this is a fairly straight-forward PR that mainly touches the build system. Are you able to ack?

[evgeniy-paltsev]

Does ARC MWDT have something like -nostdinc++ from GCC? If so, we should specify the nostdincxx property for the MWDT as well.

@stephanosio I guess we do similar thing for MWDT but in a slightly different way:
cmake/compiler/arcmwdt/target.cmake

if(CONFIG_ARCMWDT_LIBC AND CONFIG_LIB_CPLUSPLUS)
  list(APPEND NOSTDINC ${TOOLCHAIN_HOME}/arc/lib/src/c++/inc)
endif()

foreach(isystem_include_dir ${NOSTDINC})
  list(APPEND isystem_include_flags -isystem "\"${isystem_include_dir}\"")
endforeac

[tejlmand]

The compiler flags should simply specify flags, not decide whether they should be used or not.

[tejlmand]

thanks. good to get things like this cleaned up.