[tlbuild] pretest initial builds please

[Akira Kakuto]

Dear Marc,

> !pdfTeX error: pdflatex
> (file /usr/local/texlive/2017/texmf-var/fonts/map/pdftex/updmap/pdftex.map):
> buffer overflow at file ../../../texk/web2c/pdftexdir/mapfile.c, line 416

It seems that pdftex checks line-ending charcter 0x0a near line 416 in mapfile.c.
Is there the line-ending charcter in all lines in your pdftex.map?

Best,
Akira