Flipped match order of label and registry address.

src/lex.l

@@ -10,8 +10,8 @@ int     [1-9][0-9]*
 [\n]                { return NL; }                              /* Newline */
 #.*                 { yylval.sval = yytext; return COMMENT; }   /* Comment */
 \..*                { yylval.sval = yytext; return DIRECTIVE; } /* Assembly directive */
-{reg}               { yylval.sval = yytext; return REG; }       /* Registry address */
 {word}:             { yylval.sval = yytext; return LABEL; }     /* Label */
+{reg}               { yylval.sval = yytext; return REG; }       /* Registry address */
 {int}               { yylval.ival = atoi(yytext); return INT; } /* Integer */
 {int}(\({reg}\))?   { yylval.sval = yytext; return OFFSET; }    /* Registry offset */
 [a-z\.]+            { yylval.sval = yytext; return INSTR; }     /* Instruction */