Verify that last argument of __builtin_expect_with_probability is a real cst (PR...

Verify that last argument of __builtin_expect_with_probability is a real cst (PR c/87811).

2018-11-05  Martin Liska  <mliska@suse.cz>

	PR c/87811
	* predict.c (expr_expected_value_1): Verify
	that last argument is a real constants and emit
	error.
2018-11-05  Martin Liska  <mliska@suse.cz>

	PR c/87811
	* gcc.dg/pr87811.c: New test.
	* gcc.dg/pr87811-2.c: Likewise.
	* gcc.dg/pr87811-3.c: Likewise.
2018-11-05  Martin Liska  <mliska@suse.cz>

	PR c/87811
	* doc/extend.texi: Update constrain about the last argument
	of __builtin_expect_with_probability.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@265785 138bc75d-0d04-0410-961f-82ee72b054a4