Fangrui Song f31a36e776 Revert D139752 "cmake: Enable 64bit off_t on 32bit glibc systems"
This reverts commit ae3e228af77fea9ff4c45cca88a7a0de2cad662b.

Seems that it may form a wrong command line for 32-bit Halide builds

`-D_FILE_OFFSET_BITS="64 -D_DEBUG -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -DSTDC_CONSTANT_MACROS -DSTDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS"` according to
2022-12-20 09:45:28 -08:00
..

See docs/CMake.html for instructions on how to build LLVM with CMake.