tree-optimization/114246 - invalid call argument from DSE

The following makes sure to strip type conversions added by
build_fold_addr_expr before placing the result in a call argument.

	PR tree-optimization/114246
	* tree-ssa-dse.cc (increment_start_addr): Strip useless
	type conversions from the adjusted address.

	* gcc.dg/torture/pr114246.c: New testcase.

(cherry picked from commit 0249744)

Author: rguenth

gcc/testsuite/gcc.dg/torture/pr114246.c

@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-w" } */
+
+int a, b;
+
+void
+foo (void)
+{
+  __builtin_memcpy (&a, (char *)&b - 1, 2);
+  __builtin_memcpy (&a, &b, 1);
+}

gcc/tree-ssa-dse.cc

@@ -48,6 +48,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree-ssa-loop-niter.h"
 #include "cfgloop.h"
 #include "tree-data-ref.h"
+#include "tree-ssa.h"
 
 /* This file implements dead store elimination.
 
@@ -643,6 +644,7 @@ increment_start_addr (gimple *stmt, tree *where, int increment)
 					      *where,
 					      build_int_cst (ptr_type_node,
 							     increment)));
+  STRIP_USELESS_TYPE_CONVERSION (*where);
 }
 
 /* STMT is builtin call that writes bytes in bitmap ORIG, some bytes are dead