[RS6000] Remove constraints on call rounded_stack_size_rtx arg

[RS6000] Remove constraints on call rounded_stack_size_rtx arg

This call arg is unused on rs6000.

	* config/rs6000/darwin.md (call_indirect_nonlocal_darwin64),
	(call_nonlocal_darwin64, call_value_indirect_nonlocal_darwin64),
	(call_value_nonlocal_darwin64): Remove constraints from second call
	arg, the rounded_stack_size_rtx arg.
	* config/rs6000/rs6000.md (tls_gd_aix, tls_gd_sysv, tls_gd_call_aix),
	(tls_gd_call_sysv, tls_ld_aix, tls_ld_sysv, tls_ld_call_aix),
	(tls_ld_call_sysv, call_local32, call_local64, call_value_local32),
	(call_value_local64, call_indirect_nonlocal_sysv),
	(call_nonlocal_sysv, call_nonlocal_sysv_secure),
	(call_value_indirect_nonlocal_sysv, call_value_nonlocal_sysv),
	(call_value_nonlocal_sysv_secure, call_local_aix),
	(call_value_local_aix, call_nonlocal_aix, call_value_nonlocal_aix),
	(call_indirect_aix, call_value_indirect_aix, call_indirect_elfv2),
	(call_value_indirect_elfv2, sibcall_local32, sibcall_local64),
	(sibcall_value_local32, sibcall_value_local64, sibcall_aix),
	(sibcall_value_aix): Likewise.

From-SVN: r266603