SYCL-JIT: disable PCH reuse (#35314)
Fix extra warnings/errors like:
```
nblog2.log: 13595: In file included from /netbatch/build_comp63266_00/ics_top/llvm/llvm/include/llvm/IR/Metadata.h:35:
nblog2.log: 13596: /netbatch/build_comp63266_00/ics_top/llvm/llvm/include/llvm/ADT/ArrayRef.h:79:35: error: implicit conversion changes signedness: 'long' to 'size_type' (aka 'unsigned long') [-Werror,-Wsign-conversion]
nblog2.log: 13597: 79 | : Data(begin), Length(end - begin) {
nblog2.log: 13598: | ~~~~~^~~~~~~
nblog2.log: ...
nblog2.log: 13843: make[2]: *** [tools/sycl-jit/passes/CMakeFiles/SYCLJITPasses.dir/build.make:78: tools/sycl-jit/passes/CMakeFiles/SYCLJITPasses.dir/SYCLJITPasses.cpp.o] Error 1
```
