[AArch64] Add SVE conditional conversion patterns

[AArch64] Add SVE conditional conversion patterns

This patch adds patterns to match conditional conversions between
integers and like-sized floats.  The patterns are actually more
general than that, but the other combinations can only be tested
via the ACLE.

2019-08-14  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* config/aarch64/aarch64-sve.md
	(*cond_<SVE_COND_FCVTI:optab>_nontrunc<SVE_F:mode><SVE_HSDI:mode>)
	(*cond_<SVE_COND_ICVTF:optab>_nonextend<SVE_HSDI:mode><SVE_F:mode>):
	New patterns.

gcc/testsuite/
	* gcc.target/aarch64/sve/cond_convert_1.c: New test.
	* gcc.target/aarch64/sve/cond_convert_1_run.c: Likewise.
	* gcc.target/aarch64/sve/cond_convert_2.c: Likewise.
	* gcc.target/aarch64/sve/cond_convert_2_run.c: Likewise.
	* gcc.target/aarch64/sve/cond_convert_3.c: Likewise.
	* gcc.target/aarch64/sve/cond_convert_3_run.c: Likewise.
	* gcc.target/aarch64/sve/cond_convert_4.c: Likewise.
	* gcc.target/aarch64/sve/cond_convert_4_run.c: Likewise.
	* gcc.target/aarch64/sve/cond_convert_5.c: Likewise.
	* gcc.target/aarch64/sve/cond_convert_5_run.c: Likewise.
	* gcc.target/aarch64/sve/cond_convert_6.c: Likewise.
	* gcc.target/aarch64/sve/cond_convert_6_run.c: Likewise.

From-SVN: r274478