Last testcase for PR middle-end/25140

[Jan Hubicka]

Hi,
I checked the ipa-pta and pta implementations and these seems to work just
fine with presence of aliases because get_constraint_for_ssa_var already
looks into the alias targets.

This patch adds a testcase I constructed.  Since I am done with auditing
*alias*.c for variable aliases I will close the PR (after 10 years, yay)

Honza

	PR middle-end/25140
	* gcc.c-torture/execute/alias-4.c: New testcase.
Index: testsuite/gcc.c-torture/execute/alias-4.c
===================================================================
--- testsuite/gcc.c-torture/execute/alias-4.c	(revision 0)
+++ testsuite/gcc.c-torture/execute/alias-4.c	(revision 0)
@@ -0,0 +1,19 @@
+/* { dg-require-alias "" } */
+int a = 1;
+extern int b __attribute__ ((alias ("a")));
+int c = 1;
+extern int d __attribute__ ((alias ("c")));
+main (int argc)
+{
+  int *p;
+  int *q;
+  if (argc)
+    p = &a, q = &b;
+  else
+    p = &c, q = &d;
+  *p = 1;
+  *q = 2;
+  if (*p == 1)
+    __builtin_abort ();
+  return 0;
+}