[libc] Use proper flags for compiler version detection

The `-v` flag means verbose and not version.
With `clang` this flag prints the version and exits successfully.
Under `GCC` this is not a valid command line so the binary exits with
an error.

libc/cmake/modules/LLVMLibCArchitectures.cmake

@@ -76,7 +76,7 @@ function(get_arch_and_system_from_triple triple arch_var sys_var)
   set(${sys_var} ${target_sys} PARENT_SCOPE)
 endfunction(get_arch_and_system_from_triple)
 
-execute_process(COMMAND ${CMAKE_CXX_COMPILER} -v
+execute_process(COMMAND ${CMAKE_CXX_COMPILER} --version -v
                 RESULT_VARIABLE libc_compiler_info_result
                 OUTPUT_VARIABLE libc_compiler_info
                 ERROR_VARIABLE libc_compiler_info)