AArch64: Remove "fndecl && TREE_PUBLIC (fndecl)" in aarch64_init_cumulative_args

AArch64: Remove "fndecl && TREE_PUBLIC (fndecl)" in aarch64_init_cumulative_args

This check will prevent the function type check of static funtion or calling
via a funtion pointer. The function type should be checked no matter if the
function has external linkage.

gcc/ChangeLog:

	* config/aarch64/aarch64.c (aarch64_init_cumulative_args): Remove
	"fndecl && TREE_PUBLIC (fndecl)" check since it prevents the funtion
	type check when calling via a function pointer or when calling a static
	function.

gcc/testsuite/ChangeLog:

	* gcc.target/aarch64/mgeneral-regs_7.c: New test.