parser: Get rid of PEOA

PEOA is a special character used to mark an alias as being finished
so that we don't enter an infinite loop with nested aliases.  It
complicates the parser because we have to ensure that it is skipped
where necessary and not copied to the resulting token text.

This patch removes it and instead delays the marking of aliases
until the second pgetc.  This has the same effect as the current
PEOA code while keeping the complexities within the input code.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
4 files changed