nir: Handle <bits>=32 case in bitfield_insert lowering.

nir: Handle <bits>=32 case in bitfield_insert lowering.

The OpenGL specifications for bitfieldInsert() says:

   The result will be undefined if <offset> or <bits> is negative, or if
   the sum of <offset> and <bits> is greater than the number of bits
   used to store the operand.

Therefore passing bits=32, offset=0 is legal and defined in GLSL.

But the earlier SM5 bfi opcode is specified to accept a bitfield width
ranging from 0-31. As such, Intel and AMD instructions read only the low
5 bits of the width operand, making them not able to implement the
GLSL-specified behavior directly.

This commit fixes the lowering of bitfield_insert to handle the trivial
case of <bits> = 32 as

   bitfieldInsert:
      bits > 31 ? insert : bfi(bfm(bits, offset), insert, base)

Fixes:
   ES31-CTS.shader_bitfield_operation.bitfieldInsert.uint_2
   ES31-CTS.shader_bitfield_operation.bitfieldInsert.uvec4_3
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=92595
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Tested-by: Marta Lofstedt <marta.lofstedt@intel.com>