Fix remove_stmt in vectorizable_simd_clone_call (PR 86758)

vectorizable_simd_clone_call was trying to remove a pattern statement
instead of the original statement,  Fixes existing tests
gcc.dg/pr84452.c and gcc.target/i386/pr84309.c on x86.

2018-08-01  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	PR tree-optimization/86748
	* tree-vect-stmts.c (vectorizable_simd_clone_call): Don't try
	to remove pattern statements.

From-SVN: r263222

gcc/ChangeLog

 2018-08-01  Richard Sandiford  <richard.sandiford@arm.com>
 
+	PR tree-optimization/86748
+	* tree-vect-stmts.c (vectorizable_simd_clone_call): Don't try
+	to remove pattern statements.
+
+2018-08-01  Richard Sandiford  <richard.sandiford@arm.com>
+
 	* tree-vect-loop.c (_loop_vec_info::_loop_vec_info): Use the
 	result of dfs_enumerate_from when constructing stmt_vec_infos,
 	instead of additionally calling get_loop_body.

gcc/tree-vect-stmts.c

@@ -4368,7 +4368,7 @@ vectorizable_simd_clone_call (stmt_vec_info stmt_info,
     }
   else
     new_stmt = gimple_build_nop ();
-  vinfo->replace_stmt (gsi, stmt_info, new_stmt);
+  vinfo->replace_stmt (gsi, vect_orig_stmt (stmt_info), new_stmt);
   unlink_stmt_vdef (stmt);
 
   return true;