Merge branch 'mr/llvm-equivalent-of-general-regs-only' into 'master'

Use -mno-implicit-float for GNAT-LLVM instead of -mgeneral-regs-only

See merge request eng/toolchain/bb-runtimes!80

aarch64/__init__.py

@@ -84,7 +84,11 @@ def amend_rts(self, rts_profile, conf):
         # switch and does so by doing lazy context switches: this restores
         # the registers only when they are used by apps. This means that if
         # a FPU register is used out of context, then we're doomed.
-        conf.build_flags["common_gnarl_flags"] += ["-mgeneral-regs-only"]
+        conf.build_flags["common_gnarl_flags"] += [
+            "-mgeneral-regs-only"
+            if not using_llvm_compiler()
+            else "-mno-implicit-float"
+        ]
 
     def dump_runtime_xml(self, rts_name, rts):
         cnt = super(Aarch64Target, self).dump_runtime_xml(rts_name, rts)