Merge pull request #408 from messense/mips64-musl-float

Add compiler-rt fallbacks on mips64-musl

library/compiler-builtins/build.rs

@@ -449,6 +449,8 @@ mod c {
                 ("__fixunstfsi", "fixunstfsi.c"),
                 ("__floatunsitf", "floatunsitf.c"),
                 ("__fe_getround", "fp_mode.c"),
+                ("__divtf3", "divtf3.c"),
+                ("__trunctfdf2", "trunctfdf2.c"),
             ]);
         }