Change name and usage of presym macros

To be also able to build mruby without presym in the future. However,
`MRB_QSYM` has been removed and changed as follows:

### Example

|       Type                | Symbol |  Previous Style  |   New Style    |
|---------------------------|--------|------------------|----------------|
| Operator                  | &      | MRB_QSYM(and)    | MRB_OPSYM(and) |
| Class Variable            | @@foo  | MRB_QSYM(00_foo) | MRB_CVSYM(foo) |
| Instance Variable         | @foo   | MRB_QSYM(0_foo)  | MRB_IVSYM(foo) |
| Method with Bang          | foo!   | MRB_QSYM(foo_b)  | MRB_SYM_B(foo) |
| Method with Question mark | foo?   | MRB_QSYM(foo_p)  | MRB_SYM_Q(foo) |
| Mmethod with Equal        | foo=   | MRB_QSYM(foo_e)  | MRB_SYM_E(foo) |

This change makes it possible to define, for example, `MRB_IVSYM(foo)` as
`mrb_intern_lit(mrb, "@" "foo")`, which is useful if we support building
without presym in the future.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/object.c b/src/object.c
index aaab4022d..bf4d743ff 100644
--- a/src/object.c
+++ b/src/object.c
@@ -58,7 +58,7 @@ mrb_equal(mrb_state *mrb, mrb_value obj1, mrb_value obj2)
       return TRUE;
   }
 #endif
-  result = mrb_funcall_id(mrb, obj1, MRB_QSYM(eq), 1, obj2);
+  result = mrb_funcall_id(mrb, obj1, MRB_OPSYM(eq), 1, obj2);
   if (mrb_test(result)) return TRUE;
   return FALSE;
 }
@@ -660,5 +660,5 @@ MRB_API mrb_bool
 mrb_eql(mrb_state *mrb, mrb_value obj1, mrb_value obj2)
 {
   if (mrb_obj_eq(mrb, obj1, obj2)) return TRUE;
-  return mrb_test(mrb_funcall_id(mrb, obj1, MRB_QSYM(eql_p), 1, obj2));
+  return mrb_test(mrb_funcall_id(mrb, obj1, MRB_SYM_Q(eql), 1, obj2));
 }