[NTVDM] REGRESSION many games now fail on start with "Waiting for new command..." (only GCC affected)

many games now fail on start with "Waiting for new command..." in NTVDM

FAILS OCCUR ONLY ON GCC BUILDS

This is a regression.
Reg-testing Prince Of Persia 1 which ran fine before.

r69219 MSVC POP1 runs fine
r69219 GCC POP1 fail "Waiting for new command..."
r69216 GCC POP1 fail "Waiting for new command..."
r69210 GCC POP1 fail "Waiting for new command..."
r69206 GCC POP1 fail "Waiting for new command..."
r69206 MSVC POP1 runs fine
r69205 does not compile on GCC subsystems/mvdm/ntvdm/dos/dem.c:1439:13: error: suggest parentheses around '&&' within '||'
r69204 does not compile on GCC subsystems/mvdm/ntvdm/dos/dem.c:1439:13: error: suggest parentheses around '&&' within '||'

r69203 unfortunately I don't get ROS to boot this revision
r69202 GCC POP1 runs fine
r69201 GCC POP1 runs fine
r69188 GCC POP1 runs fine

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so it seems like r69203 started breaking GCC builds and r69206 made them least compile again, but left lots of games relying on NTVDM broken.

Affected games I found so far:
Prince of persia 1
one must fall 2097
pushover
command & conquer