Move tests of cabs and carg from libm-test.inc to auto-libm-test-in.

Move tests of cabs and carg from libm-test.inc to auto-libm-test-in.

This patch moves tests of cabs and carg to auto-libm-test-in, adding
the required support to gen-auto-libm-tests.

Tested x86_64 and x86; no ulps updates needed.

	* math/auto-libm-test-in: Add tests of cabs and carg.
	* math/auto-libm-test-out: Regenerated.
	* math/libm-test.inc (cabs_test_data): Use AUTO_TESTS_c_f.
	(carg_test_data): Likewise.
	* math/gen-auto-libm-tests.c (func_calc_method): Add value
	mpc_c_f.
	(func_calc_desc): Add mpc_c_f union field.
	(test_functions): Add cabs and carg.
	(calc_generic_results): Handle mpc_c_f.