A missing factor in an expression causes an expected but missing token
to be skipped, leading to invalid flagged errors in the following line:
l = 3 +
lda #$00
An error should be output for line 1, but not for line 2. Actually, both
are flagged as errors:
test.s(1): Error: Syntax error
test.s(2): Error: Unexpected trailing garbage characters
This patch (as proposed in issue #1634 by kugelfuhr) fixes this.