[AArch64] Specify fp16 support for Cortex-A55 and Cortex-A75

The Cortex-A55 and Cortex-A75 processors support the fp16 extension.
We already specify them as such in the arm port.
This patch makes aarch64 consistent on this front.

Bootstrapped and tested on aarch64-none-linux-gnu.
Manually checked that compiling with aarch64-none-linux-gnu-gcc -mcpu=cortex-a55 -dM -E - < /dev/null
shows __ARM_FEATURE_FP16_VECTOR_ARITHMETIC and __ARM_FEATURE_FP16_SCALAR_ARITHMETIC being specified
as expected whereas they were not before this patch.

	* config/aarch64/aarch64-cores.def (cortex-a55, cortex-a75,
	cortex-a75.cortex-a55): Specify AARCH64_FL_F16 in the arch features.

From-SVN: r255624

gcc/ChangeLog

+2017-12-14  Kyrylo Tkachov  <kyrylo.tkachov@arm.com>
+
+	* config/aarch64/aarch64-cores.def (cortex-a55, cortex-a75,
+	cortex-a75.cortex-a55): Specify AARCH64_FL_F16 in the arch features.
+
 2017-12-14  Richard Sandiford  <richard.sandiford@linaro.org>
 	    Alan Hayward  <alan.hayward@arm.com>
 	    David Sherwood  <david.sherwood@arm.com>

gcc/config/aarch64/aarch64-cores.def

@@ -83,8 +83,8 @@ AARCH64_CORE("thunderx2t99",  thunderx2t99,  thunderx2t99, 8_1A,  AARCH64_FL_FOR
 /* ARMv8.2-A Architecture Processors.  */
 
 /* ARM ('A') cores. */
-AARCH64_CORE("cortex-a55",  cortexa55, cortexa53, 8_2A,  AARCH64_FL_FOR_ARCH8_2 | AARCH64_FL_RCPC | AARCH64_FL_DOTPROD, cortexa53, 0x41, 0xd05, -1)
-AARCH64_CORE("cortex-a75",  cortexa75, cortexa57, 8_2A,  AARCH64_FL_FOR_ARCH8_2 | AARCH64_FL_RCPC | AARCH64_FL_DOTPROD, cortexa73, 0x41, 0xd0a, -1)
+AARCH64_CORE("cortex-a55",  cortexa55, cortexa53, 8_2A,  AARCH64_FL_FOR_ARCH8_2 | AARCH64_FL_F16 | AARCH64_FL_RCPC | AARCH64_FL_DOTPROD, cortexa53, 0x41, 0xd05, -1)
+AARCH64_CORE("cortex-a75",  cortexa75, cortexa57, 8_2A,  AARCH64_FL_FOR_ARCH8_2 | AARCH64_FL_F16 | AARCH64_FL_RCPC | AARCH64_FL_DOTPROD, cortexa73, 0x41, 0xd0a, -1)
 
 /* ARMv8.3-A Architecture Processors.  */
 
@@ -100,6 +100,6 @@ AARCH64_CORE("cortex-a73.cortex-a53",  cortexa73cortexa53, cortexa53, 8A,  AARCH
 
 /* ARM DynamIQ big.LITTLE configurations.  */
 
-AARCH64_CORE("cortex-a75.cortex-a55",  cortexa75cortexa55, cortexa53, 8_2A,  AARCH64_FL_FOR_ARCH8_2 | AARCH64_FL_RCPC | AARCH64_FL_DOTPROD, cortexa73, 0x41, AARCH64_BIG_LITTLE (0xd0a, 0xd05), -1)
+AARCH64_CORE("cortex-a75.cortex-a55",  cortexa75cortexa55, cortexa53, 8_2A,  AARCH64_FL_FOR_ARCH8_2 | AARCH64_FL_F16 | AARCH64_FL_RCPC | AARCH64_FL_DOTPROD, cortexa73, 0x41, AARCH64_BIG_LITTLE (0xd0a, 0xd05), -1)
 
 #undef AARCH64_CORE