enum snake_case check

vlib/compiler/enum.v

@@ -25,6 +25,9 @@ fn (p mut Parser) enum_decl(_enum_name string) {
 	mut fields := []string
 	for p.tok == .name {
 		field := p.check_name()
+		if contains_capital(field) {
+			p.warn('enum values cannot contain uppercase letters, use snake_case instead')
+		}
 		fields << field
 		p.fgenln('')
 		name := '${mod_gen_name(p.mod)}__${enum_name}_$field'

vlib/compiler/parser.v

@@ -1544,7 +1544,8 @@ fn (p mut Parser) var_decl() {
 			p.error_with_token_index('redefinition of `$var_name`', var_token_idx)
 		}
 		// mut specified with assignment
-		if /*is_assign && implicit*/ known_var && var_is_mut {
+		//if /*is_assign && implicit*/ known_var && var_is_mut {
+		if known_var && var_is_mut {
 			p.error_with_token_index('cannot specify mutability for existing var `$var_name`, only for new vars', var_token_idx)
 		}
 		// assignment, but var does not exist