sysv/ms_abi attribute fix, part 2, avoid caching of call used in dataflow

[Jan Hubicka]

Hi,
dataflow is giving wrong results when foreign ABI is used, because
df_invalidated_by_call is converted into reg-set and cached over whole
compilation.

Kenny, perhaps cleaner approach would be to make df_invalidated_by_call
regs_invalidated_by_call_regset initialized by regcalss's init_regs
where all the other stuff is initialized.  If this is preferred
solution, I will prepare updated patch.

	Jan Hubicka  <jh@suse.cz>
	Kai Tietz <kai.tietz@onevision.com>
	* df-scan.c (df_hard_reg_init): Always recompute df_invalidated_by_call
	bitmap.
Index: df-scan.c
===================================================================
*** df-scan.c	(revision 142597)
--- df-scan.c	(working copy)
*************** df_hard_reg_init (void)
*** 4119,4125 ****
    static const struct {const int from, to; } eliminables[] = ELIMINABLE_REGS;
  #endif
    if (initialized)
!     return;
  
    bitmap_obstack_initialize (&persistent_obstack);
  
--- 4119,4133 ----
    static const struct {const int from, to; } eliminables[] = ELIMINABLE_REGS;
  #endif
    if (initialized)
!     {
!       bitmap_clear (df_invalidated_by_call);
!       /* Inconveniently, this is only readily available in hard reg set
! 	 form and moreover can change in between functions.  */
!       for (i = 0; i < FIRST_PSEUDO_REGISTER; ++i)
! 	if (TEST_HARD_REG_BIT (regs_invalidated_by_call, i))
! 	  bitmap_set_bit (df_invalidated_by_call, i);
!       return;
!     }
  
    bitmap_obstack_initialize (&persistent_obstack);