CMake: properly detect when to rebuild zig1.o

This is andrewrk's patch from ziglang#6724 (rebased)

CMake: Fix dependency problem

I don't know whether the error was expected cmake behavior or a bug.
This change seems to fix the issue. See ziglang#6724 for details.

cmake: add the correct set of zig stage2 sources
51ffb0548djohnLate committed on 11/17/2020, 1:04:54 AM· committed by Andrew Kelleyparent5b42704
1 file changedLine totals unavailable