FIx regression with member tag of enum not being checked on assigment

This fixes regression introduced in AMXX 1.60: https://github.com/alliedmodders/amxmodx/commit/a105bc740282c568109a0280bb51a327718792d2

Original fix removes tag mismatch warning in such situation:
```PAWN
enum GABEGG
{
    GABEN_CONST_1,
    GABEN_CONST_2,
};

new Float:MyArray_2[GABEGG];

MyArray_2[GABEN_CONST_1] = 42.0; // no more warning
```

But introduced a regression when tagged members of enum is used.
Tag check is processed with `MyArray` instead of member tag.
```PAWN
enum GABEN
{
    MyTag:m_Gaben_1,
    Float:m_Gaben_2,
    Regex:m_Gaben_3,
    bool:m_Gaben_4,
    m_Gaben_5
};

new MyArray[GABEN];
```
With original fix, member tag is ignored and coder has to rely on `_:` to untag before:
```PAWN
MyArray[m_Gaben_1] = MyTag:42;                      // warning
MyArray[m_Gaben_2] = _:42.0;                        
MyArray[m_Gaben_2] = 42.0;                          // warning
MyArray[m_Gaben_2] = 42;                            // no warning, it should have one
MyArray[m_Gaben_3] = _:regex_compile("Something");  
MyArray[m_Gaben_3] = regex_compile("Something");    // warning
MyArray[m_Gaben_3] = Regex:42;                      // warning
MyArray[m_Gaben_4] = true;                          
MyArray[m_Gaben_5] = 42; 
```
With new fix, trick with `_:` is kept, while member tag is now checked:
```PAWN
MyArray[m_Gaben_1] = MyTag:42;                      
MyArray[m_Gaben_2] = _:42.0;                        // no warning for compatibility
MyArray[m_Gaben_2] = 42.0;                          
MyArray[m_Gaben_2] = 42;                            // warning, expects a Float
MyArray[m_Gaben_3] = _:regex_compile("Something");  // no warning for compatibility
MyArray[m_Gaben_3] = regex_compile("Something");   
MyArray[m_Gaben_3] = Regex:42;                      
MyArray[m_Gaben_4] = true;                          
MyArray[m_Gaben_5] = 42;  

MyArray_2[GABEN_CONST_1] = 42.0;                    // still no warning       
```

I hope I did not forget something and that it looks enough sane.
Tell me your thoughts David.
Semantically this comment is a little strange, since by definition `Float:array[X]` *is* an enum struct, it's just been tagged improperly. Correct code would be adding a third enumeration called "Total" or something, and the provided declaration is just bogus. Maybe it's too late to start rejecting those. It's also odd since you can still tag constants of the enum.

But if your intent is to define things this way, no objections from me. Enum structs are persona-non-grata in SP :)

Comment suggestion:

```
// If the left value is a tagged symbol, assume that it is not an "enum struct." For
// example, for "enum X { A, B }; new Float:array[X]" we assume that `A` and `B`
// are not tagged and the array is an array of floats.
```