I've tried on some of the systems I have at hand, and it looks like a v5.8.8 bug :

Confirmed under the Redmondish side of the world, too:

C:\temp>perl -e "for (2,2) {print;warn}"
Warning: something's wrong at -e line 1.
Warning: something's wrong at -e line 1.
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Note that I wanted to further simplify the test code, but the bug doesn't seem to show up with a c<for> statement modifier:

C:\temp>perl -e "print,warn for 2,2"
Warning: something's wrong at -e line 1.
Warning: something's wrong at -e line 1.
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BTW: what if $@ is set?

C:\temp>perl -e "$@='all your base are belong to us';for (2,2) {print;
+warn}"
all your base are belong to us  ...caught at -e line 1.
all your base are belong to us  ...caught       ...caught at -e line 1
+.
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Nope, the bug is still there...