[autovect][patch]Remove unnecessary call to mark_call_clobbered_vars_to_rename

[Keith Besaw <kbesaw at us dot ibm dot com>]

Remove the call to mark_call_clobbered_vars_to_rename generated for the
CALL_EXPR to the builtin targetm.vectorize.builtin_mask_for_load. 
Currently
the only definition of builtin targetm.vectorize.builtin_mask_for_load is 
from
config/rs6000.c where the builtin is declared "const".  It is expected 
that the
builtin would be "const" for any other architectures that declared it in 
the future.
A gcc_assert has been inserted to ensure this.

This change is one more step in removing any need for tree-vectorizer.c to
call rewrite_into_ssa to do variable renaming.

Keith

Index: tree-vectorizer.c
===================================================================
RCS file: /cvsroot/gcc/gcc/gcc/tree-vectorizer.c,v
retrieving revision 2.25.2.11
diff -c -3 -p -r2.25.2.11 tree-vectorizer.c
*** tree-vectorizer.c   30 Jan 2005 18:11:03 -0000      2.25.2.11
--- tree-vectorizer.c   2 Feb 2005 05:30:59 -0000
*************** vectorizable_load (tree stmt, block_stmt
*** 3012,3020 ****
          gcc_assert (!new_bb);
          magic = TREE_OPERAND (new_stmt, 0);
 
!         /* Since we have just created a CALL_EXPR, we may need to
!            rename call-clobbered variables.  */
!         mark_call_clobbered_vars_to_rename ();
        }
        else
        {
--- 3017,3029 ----
          gcc_assert (!new_bb);
          magic = TREE_OPERAND (new_stmt, 0);
 
!           /* The result of the CALL_EXPR to this builtin is determined 
from
!              the value of the parameter and no global variables are 
touched
!              which makes the builtin a "const" function.  Requiring the
!              builtin to have the "const" attribute makes it unnecessary
!              to call mark_call_clobbered_vars_to_rename.  */
!         gcc_assert (TREE_READONLY (builtin_decl));
! 
        }
        else
        {