[PATCH 00/17] Move builtin functions to range-ops.

[Andrew MacLeod <amacleod@redhat.com>]

Builtin functions have been handled until now as special cases in 
gimple-range-fold.cc. This set of patches makes the changes required to 
create a range_operator for those functions.  This allows them to behave 
like a normal unary/binary operation through out the ranger ecosystem.  
In particular, it will enable us to make GORI aware of them as we can 
now provide op1_range and op2_range routines, as well as registering an 
relations as needed.  None of these enhanced functions are provided yet, 
this is strictly a conversion.  This enables us to do this for any 
operation with 1 or 2 operands.

There are 17 patches, some are bug fixes, some are infrastructure, a 
couple are just missing functionality, but most are them are conversions 
of the builtins.  I did each builtin as a separate patch so if a 
regression triggers, we can pinpoint it faster.

Of note:

Patch 2 : Modifies the range_op_handler class to store an integer 
handler and a float handler rather than the old tree-code and type.  By 
looking up the handler immediately and storing the pointer, this opens 
up the possibility of processing handlers which are not in a tree-code 
table.

Patch 3 : Range-ops is suppose to be IL independent, designed to work in 
RTL land as well.  A little bit of gimple had crept in, and I needed a 
layer that is gimple aware.  This patch introduces a 
gimple_range_op_handler which inherits from range_op_handler, and acts 
as the connector between the gimple IL and range-ops. Some of that code 
was in range-ops, and a lot more was located in the GORI file.  All 
those bits and pieces have been moved into the new class.

Patch 7 : This patch adjusts gimple_range_op_handler constructor to also 
check if a builtin function call might have a range_operator object 
available, and if so, return that.  This initial conversion also adds 
CFN_BUILT_IN_CONSTANT_P as the first builtin, removing it from the big 
switch in gimple-range-fold.cc.

Patch 8-16 :  Moves SIGNBIT, TOUPPER/LOWER, POPCOUNT, CLZ, CTZ, CLRSB, 
UBSAN*, STRLEN, and GOACC to range-ops.

patch 17: Finally, moves CFA_BUILT_IN_PARITY to range-ops, and removes 
the builtin-function code checks from range_of_call in gimple_range-fold.cc

These patches all bootstrap on x86_64-pc-linux-gnu with no regressions. 
   Performance wise, it all ends up as approximately a wash. (VRP a hair 
slower, threading a hair faster)

Pushed.

Andrew