MSTA: small inconsistency wrt to yacc behaviour

[rofl0r]

bison and byacc both assign default action { $$ = $1; } to expression as below:

mnemonic: MN_JMP
 | MN_JZ
 | MN_JNZ
 ;

so that the result is identical to

mnemonic: MN_JMP { $$ = $1; }
 | MN_JZ   { $$ = $1; }
 | MN_JNZ   { $$ = $1; }
 ;

MSTA instead (even in yacc mode) creates different, incompatible (and quite big) piece of code for every line in the expression.
i'm not sure whether this is documented behaviour, but it'd be nice to have it supported when using MSTA as yacc replacement.

[vnmakarov]

OK. Thanks for reporting this. I designed this code 30 years ago and there are a lot of optimizations in the parser, especially for rule reductions and attribute passing. So the code you see might be an optimized version of the code for parsing by several rules. I'll investigate this when I have time.