always define STACK_GROWS_DOWNWARD

always define STACK_GROWS_DOWNWARD

gcc/c-family/ChangeLog:

2015-05-20  Trevor Saunders  <tbsaunde+gcc@tbsaunde.org>

	* c-cppbuiltin.c (c_cpp_builtins): Check the value of
	STACK_GROWS_DOWNWARD rather than if it is defined.

gcc/ChangeLog:

2015-05-20  Trevor Saunders  <tbsaunde+gcc@tbsaunde.org>

	* *.c: Check the value of STACK_GROWS_DOWNWARD rather than if it
	is defined.
	* config/**/*.h: Define STACK_GROWS_DOWNWARD to an integer.
	* defaults.h: Provide default for STACK_GROWS_DOWNWARD.
	* doc/tm.texi.in: Update references to STACK_GROWS_DOWNWARD.
	* doc/tm.texi: Regenerate.

From-SVN: r223513