Build fails is `pthread_getname_np` is unavailable, since nothing actually checks for it

[barracuda156]

Describe the bug

This code does not work as supposed to, if pthread_getname_np is unavailable:

aws-c-common/source/posix/thread.c

Lines 506 to 528 in cde20c6

	int aws_thread_name(struct aws_allocator *allocator, aws_thread_id_t thread_id, struct aws_string **out_name) {
	*out_name = NULL;
	#if defined(AWS_PTHREAD_GETNAME_TAKES_2ARGS) || defined(AWS_PTHREAD_GETNAME_TAKES_3ARGS) || \
	defined(AWS_PTHREAD_GET_NAME_TAKES_2_ARGS)
	char name[THREAD_NAME_BUFFER_SIZE] = {0};
	# ifdef AWS_PTHREAD_GETNAME_TAKES_3ARGS
	if (pthread_getname_np(thread_id, name, THREAD_NAME_BUFFER_SIZE)) {
	# elif AWS_PTHREAD_GETNAME_TAKES_2ARGS
	if (pthread_getname_np(thread_id, name)) {
	# elif AWS_PTHREAD_GET_NAME_TAKES_2ARGS
	if (pthread_get_name_np(thread_id, name)) {
	# endif
	return aws_raise_error(AWS_ERROR_SYS_CALL_FAILURE);
	}
	*out_name = aws_string_new_from_c_str(allocator, name);
	return AWS_OP_SUCCESS;
	#else
	return aws_raise_error(AWS_ERROR_PLATFORM_NOT_SUPPORTED);
	#endif
	}

Regression Issue

• Select this option if this issue appears to be a regression.

Expected Behavior

The build must check for pthread_getname_np and fall back to AWS_ERROR_PLATFORM_NOT_SUPPORTED, but not fail to compile.

Current Behavior

thread.c:512:9: error: implicit declaration of function 'pthread_getname_np'

Reproduction Steps

Run the build on a system without pthread_getname_np.

Possible Solution

Add a check for the function in question.

Additional Information/Context

No response

aws-c-common version used

0.12.4

Compiler and version used

gcc 14.2.0

Operating System and version

macOS 10.5.8

[azkrishpy]

MacOS 10.15+ is what c-common is supported and tested on. However, #1224 should fix the compiler error.