@Campbell Barton (campbellbarton) found the issue here.

In blender/editors/object/object_add.c:1994 we convert the text object to a curve first, this causes the order in which the geometry indices are build to be reversed.
However, it seems like the current code can convert OB_FONT without any problems so if I remove that conversion, it seems to work fine.

I'm guessing that is is like this for a reason or is this simply something that is not needed anymore and can be removed?

I should also note that there seems to be a mem leak here too when converting to mesh:
Error: Not freed memory blocks: 15, total unfreed memory 0.032776 MB

Mem Leak might also be related to T60211

Build modifier for Text still works in reversed order.

System Information
Operating system: Linux-4.15.0-20-lowlatency-x86_64-with-debian-buster-sid 64 Bits
Graphics card: Mesa DRI Intel(R) Haswell Mobile Intel Open Source Technology Center 4.5 (Core Profile) Mesa 18.0.0-rc5

Blender Version
Broken: version: 2.82 (sub 7), branch: master, commit date: 2020-03-12 05:06, hash: rB375c7dc4caf4
Broken: version: 2.83 (sub 17), branch: master, commit date: 2020-05-22 19:52, hash: rBe8dd8c2829f3

The issue reported here was that the build modifier would switch directions when converting a text object into a mesh.
This is not the case anymore so that issue is fixed.

Hello,

Build modifier for Text still works in reversed order.
I think what is expected here is that, with this build modifier and text, first letter appear, then second letter, then third ... But here is first the last letter...

Thank you!