re PR tree-optimization/38997 (-ftree-loop-distribution ICEs)

gcc/
	PR tree-optimization/38997
	* tree-loop-distribution.c (generate_memset_zero): Use
	POINTER_PLUS_EXPR for a pointer addition.

gcc/testsuite/
	PR tree-optimization/38997
	* gcc.dg/tree-ssa/pr38997.c: New.

From-SVN: r143740

gcc/testsuite/gcc.dg/tree-ssa/pr38997.c

+/* { dg-do compile } */
+/* { dg-options "-O2 -ftree-loop-distribution" } */
+
+int a[8][8];
+int b[8];
+
+void
+foo (int i)
+{
+  int j;
+  for (j = 0; j < 8; j++)
+    {
+      a[i][j] = 0;
+      b[j] = j;
+    }
+}