[Ada] aarch64-rtems6: use wraplf variant for a-nallfl

[Pierre-Marie de Rodat]

Since newlib doesn't implement correctly long double, use the wraplf
variant for a-nallfl.

Tested on x86_64-pc-linux-gnu, committed on trunk

gcc/ada/

        * Makefile.rtl (LIBGNAT_TARGET_PAIRS) <aarch64*-*-rtems*>: Use
        the wraplf variant of Aux_Long_Long_Float.
diff --git a/gcc/ada/Makefile.rtl b/gcc/ada/Makefile.rtl
--- a/gcc/ada/Makefile.rtl
+++ b/gcc/ada/Makefile.rtl
@@ -2193,7 +2193,7 @@ ifeq ($(strip $(filter-out rtems%,$(target_os))),)
     EH_MECHANISM=-gcc
   endif
 
-  ifeq ($(strip $(filter-out riscv%,$(target_cpu))),)
+  ifeq ($(strip $(filter-out aarch64% riscv%,$(target_cpu))),)
     LIBGNAT_TARGET_PAIRS += a-nallfl.ads<libgnat/a-nallfl__wraplf.ads
   endif
 endif