So far the REPL loop was treating any parsing error coming from
go/parser to generate the AST, as having occurred because the source
code was not yet complete (unfinished block). And it was therefore
ignoring all of them.
However, some of these errors are legitimate, and must be caught as soon
as they occur, otherwise the REPL cycle would stay in an errored state
forever (even when the block terminates), without the user getting any
feedback about it.
Therefore, this change adds an extra check when a parsing error occurs,
i.e. it verifies that it looks like an "EOF" error (unfinished block)
before it ignores it (as the user is supposed to terminate the block
eventually). Otherwise the error is treated just like a "non-parsing"
(cfg, gta, ...) error and printed out.
Fixes#637
611a8c37fa