Forbid enum redefinition.
Forbid enum redefinition.

Prevent the following code from compiling:

enum color {RED, GREEN, BLUE};
enum color {R, G, B};

int main()
{
        return R;
}

Reported-by: John Haque <31ce542d6fab7ce35fa4447731cab9846d1f7276@mchsi.com>

rchandramouli/tinycc,andreiw/tinycc,alfonsokim/tinycc,leeduhem/tinycc,fstudio/tinycc,metaeducation/tcc,mingodad/tinycc,metaeducation/tcc,andreiw/tinycc,avih/tinycc,Saectar/inherpreter,gfwilliams/tinycc,seyko2/tinycc,mingodad/tinycc,andrewchambers/tccmirror,metaeducation/tcc,fstudio/tinycc,rchandramouli/tinycc,code4game/tinycc,Saectar/inherpreter,leeduhem/tinycc,mirror/tinycc,metaeducation/tcc,mingodad/tinycc,alfonsokim/tinycc,avih/tinycc,leeduhem/tinycc,rchandramouli/tinycc,leeduhem/tinycc,run4flat/tinycc,andrewchambers/tccmirror,seyko2/tinycc,fstudio/tinycc,mirror/tinycc,gfwilliams/tinycc,avih/tinycc,andrewchambers/tccmirror,andrewchambers/tccmirror,mingodad/tinycc,gfwilliams/tinycc,Saectar/inherpreter,run4flat/tinycc,code4game/tinycc,rchandramouli/tinycc,fstudio/tinycc,run4flat/tinycc,mirror/tinycc,fstudio/tinycc,mirror/tinycc,gfwilliams/tinycc,Saectar/inherpreter,Saectar/inherpreter,seyko2/tinycc,alfonsokim/tinycc,run4flat/tinycc,andreiw/tinycc,andrewchambers/tccmirror,seyko2/tinycc,run4flat/tinycc,seyko2/tinycc,rchandramouli/tinycc,gfwilliams/tinycc,alfonsokim/tinycc,metaeducation/tcc,code4game/tinycc,avih/tinycc,alfonsokim/tinycc,leeduhem/tinycc