builtins: expand out the AEABI function stubs

These actually may change calling conventions.  We cannot simply provide
function aliases as the aliased function may have a different calling
convention.  Provide a forwarding function instead to permit the
compiler to synthesize the calling convention adjustment thunk.

Remove the `ARM_EABI_FNALIAS` macro as that is not safe to use.

Resolves PR33030!

llvm-svn: 303188
diff --git a/compiler-rt/lib/builtins/floatunsisf.c b/compiler-rt/lib/builtins/floatunsisf.c
index ea6f161..f194c04 100644
--- a/compiler-rt/lib/builtins/floatunsisf.c
+++ b/compiler-rt/lib/builtins/floatunsisf.c
@@ -18,8 +18,6 @@
 
 #include "int_lib.h"
 
-ARM_EABI_FNALIAS(ui2f, floatunsisf)
-
 COMPILER_RT_ABI fp_t
 __floatunsisf(unsigned int a) {
     
@@ -48,3 +46,10 @@
     result += (rep_t)(exponent + exponentBias) << significandBits;
     return fromRep(result);
 }
+
+#if defined(__ARM_EABI__)
+AEABI_RTABI fp_t __aeabi_ui2f(unsigned int a) {
+  return __floatunsisf(a);
+}
+#endif
+