Patch to improve x86 prologue

[Richard Henderson]

Speaking of prologue enhancements...  Another that would be
useful is to swap the order of register saves and stack allocation.
I.e. right now we have

	pushl %ebp
	movl  %esp, %ebp	[1]
	subl  $32, %esp		[2]
	pushl %edi		[3]
	pushl %esi
	pushl %ebx

We've got 3 places where we inhibit ilp.  Putting the pushes first

	pushl %ebp
	pushl %edi
	pushl %esi
	pushl %ebx
	leal  12(%esp), %ebp
	subl  $32, %esp

could speed things up.  It does make frame slot elimination 
trickier, but it can be done.

Just a thought.


r~