libfl.a and common code

[Bruce Lilly]

In flex with the reentrant option and multiple lexical analyzers,
there are multiple functions with different names but identical
code.  For example, if there are lexical analyzers with prefixes
a, b, c, ..., there will be multiple functions
aget_out, bget_out, cget_out, ...
aset_out, bset_out, cset_out, ...
alex_init, blex_init, clex_init, ...
alex_destroy, blex_destroy, c_lex_destroy, ...
etc., each set having absolutely identical code.

Such duplicate code adds unnecessary bulk to a project and fails
to take advantage of potentially common code for execution speed
(e.g. cache hits).  Wouldn't it be better to have a single set of
functions with the yy prefix and contained in libfl.a?

Of course, where code is not identical, e.g. yy_scan_buffer,
separate functions are necessary.