Add COMPILER_RT_ABI attribute to declarations of builtin functions in unittests

Summary:
This makes their local declarations match their definitions for ARM targets,
where they have a different calling convention.

This really only affects functions that use floating point types (since the
runtime functions use soft-float, and some targets may default to hard-float)
but it seemed good to make it uniform and do the int-only ones too.

Differential Revision: http://reviews.llvm.org/D9062

llvm-svn: 235722
diff --git a/compiler-rt/test/builtins/Unit/modti3_test.c b/compiler-rt/test/builtins/Unit/modti3_test.c
index ba9f980..99413aa 100644
--- a/compiler-rt/test/builtins/Unit/modti3_test.c
+++ b/compiler-rt/test/builtins/Unit/modti3_test.c
@@ -18,7 +18,7 @@
 
 // Returns: a % b
 
-ti_int __modti3(ti_int a, ti_int b);
+COMPILER_RT_ABI ti_int __modti3(ti_int a, ti_int b);
 
 int test__modti3(ti_int a, ti_int b, ti_int expected)
 {