[LyX/2.3.x] parse_text (tex2lyx): get rid of the monstrous if-then-else clause

[Juergen Spitzmueller]

commit 95d446eb4c0bd3b42874564ba7487d366bf6b1dc
Author: Juergen Spitzmueller <sp...@lyx.org>
Date:   Mon Mar 5 09:08:14 2018 +0100

    parse_text (tex2lyx): get rid of the monstrous if-then-else clause
    
    Rather than that, continue in the loop if a condition is met.
    
    This fixes tex2lyx for MINGW, which has a cluase-nesting threshold.
    
    Fixes: #9552
    (cherry picked from commit b94bb37e5310b9007ed812c58460a5292820c534)

 src/tex2lyx/text.cpp |  637 ++++++++++++++++++++++++++++++--------------------
 1 files changed, 378 insertions(+), 259 deletions(-)