[AArch64][PATCH 2/3] Adjust a utility function for floating point values.

ARMv8.2 adds 16-bit floating point operations as an optional
extension. This patch adjusts the utility function expand_fp_imm to
support 16-bit values.

The function is intended to convert an 8-bit immediate representing a
floating point value to a representation that can be passed to
fprintf. Because of the limited use of the results, the only change made
to the function is to treat a request for a 16-bit float as a request
for a 32-bit float.

opcodes/
2015-11-27  Matthew Wahab  <matthew.wahab@arm.com>

	* aarch64-opc.c (half_conv_t): New.
	(expand_fp_imm): Replace is_dp flag with the parameter size to
	specify the number of bytes for the required expansion.  Treat
	a 16-bit expansion like a 32-bit expansion.  Add check for an
	unsupported size request.  Update comment.
	(aarch64_print_operand): Update to support 16-bit floating point
	values.  Update for changes to expand_fp_imm.

Change-Id: I1ae3df3864be375d71925197ab03397ed1ad2d15