GCC static analysis support

Static analysis was introduced in GCC 10 and it is enabled with the option -fanalyzer. This option performs a much more expensive and thorough analysis of the code than traditional warnings.

Run GCC static analysis

To run GCC static analysis, west build should be called with a -DZEPHYR_SCA_VARIANT=gcc parameter, e.g.

west build -b qemu_x86 samples/userspace/hello_world_user -- -DZEPHYR_SCA_VARIANT=gcc