Use REGNUM macros in the definitions of aarch64 PROBE_STACK regs

	* config/aarch64/aarch64.c (PROBE_STACK_FIRST_REG) : Redefine as
	R9_REGNUM instead of 9.
	(PROBE_STACK_SECOND_REG): Redefine as R10_REGNUM instead of 10.

From-SVN: r267059

gcc/ChangeLog

+2018-12-12  Olivier Hainque  <hainque@adacore.com>
+
+	* config/aarch64/aarch64.c (PROBE_STACK_FIRST_REG) : Redefine as
+	R9_REGNUM instead of 9.
+	(PROBE_STACK_SECOND_REG): Redefine as R10_REGNUM instead of 10.
+
 2018-12-12  Eric Botcazou  <ebotcazou@adacore.com>
 
 	PR target/86806

gcc/config/aarch64/aarch64.c

@@ -3913,8 +3913,8 @@ aarch64_libgcc_cmp_return_mode (void)
 #endif
 
 /* The pair of scratch registers used for stack probing.  */
-#define PROBE_STACK_FIRST_REG  9
-#define PROBE_STACK_SECOND_REG 10
+#define PROBE_STACK_FIRST_REG  R9_REGNUM
+#define PROBE_STACK_SECOND_REG R10_REGNUM
 
 /* Emit code to probe a range of stack addresses from FIRST to FIRST+POLY_SIZE,
    inclusive.  These are offsets from the current stack pointer.  */