The attached patch revises the ia64 prologue skipping code.  It does a number of
things:

   1. increases the number of instructions to look at in a prologue
   2. allows looking in leaf functions
   3. recognizes indirect input register references (one level only)
   4. attempts to trust the lim_pc value

Number 1 was increased to handle some testsuite cases where the number of
parameters was quite high (e.g. 9 parameters).  No tuning was involved.

Number 4 has the biggest effect.  The line table info is more accurate except
in the case of optimized code.

Ok to commit?

-- Jeff J.

2003-05-14  Jeff Johnston  <jjohnstn@redhat.com>

	* ia64-tdep.c: Increase max_skip_non_prologue_insns to 40.
	(examine_prologue): Support looking through leaf functions, knowing
	they start with mov r2,r12.  Support skipping over indirect stores of the input
	registers.  Upon hitting a non-nop branch instruction or predicated instruction,
	bail out by setting lim_pc to the current pc value in the loop.  At the end,
	if the lim_pc value is still beyond our calculated value and we have trust_limit set,
	use the lim_pc value.