Add ARM RTABI aliases for half-precision conversions

The ARM RTABI defines these functions as __aeabi_h2f, __aeabi_f2h and
__aeabi_d2h, so we need aliases for them.

llvm-svn: 249559
diff --git a/compiler-rt/lib/builtins/truncdfhf2.c b/compiler-rt/lib/builtins/truncdfhf2.c
index 0852df369..17195cd 100644
--- a/compiler-rt/lib/builtins/truncdfhf2.c
+++ b/compiler-rt/lib/builtins/truncdfhf2.c
@@ -11,6 +11,8 @@
 #define DST_HALF
 #include "fp_trunc_impl.inc"
 
+ARM_EABI_FNALIAS(d2h, truncdfhf2)
+
 COMPILER_RT_ABI uint16_t __truncdfhf2(double a) {
     return __truncXfYf2__(a);
 }