Use DEFINE_COMPILERRT_THUMB_FUNCTION in Thumb1

Author: statham-arm

compiler-rt/lib/builtins/arm/thumb1/mulsf3.S

@@ -21,7 +21,7 @@
 
 DEFINE_AEABI_FUNCTION_ALIAS(__aeabi_fmul, __mulsf3)
 
-DEFINE_COMPILERRT_FUNCTION(__mulsf3)
+DEFINE_COMPILERRT_THUMB_FUNCTION(__mulsf3)
   PUSH {r4,r5,r6,lr}
 
   // Get exponents of the inputs, and check for uncommon values. In the process