Use `mrb_float` instead of `double` in `FIXABLE_FLOAT`.
MODIFY
include/mruby/numeric.h
include/mruby/numeric.h
@@ -23,7 +23,7 @@ MRB_BEGIN_DECL
#define NEGFIXABLE(f) TYPED_NEGFIXABLE(f,mrb_int)
#define FIXABLE(f) TYPED_FIXABLE(f,mrb_int)
#ifndef MRB_WITHOUT_FLOAT
-#define FIXABLE_FLOAT(f) TYPED_FIXABLE(f,double)
+#define FIXABLE_FLOAT(f) TYPED_FIXABLE(f,mrb_float)
#endif
#ifndef MRB_WITHOUT_FLOAT

Use `mrb_float` instead of `double` in `FIXABLE_FLOAT`.