[lldb] Improve CPUInfo test predicate

Use a with block for reading the cpuinfo file.

When loading the file fails (or we're not on Linux)
return an empty string. Since all the callers are
going to do "x in self.getCPUInfo()".

Reviewed By: omjavaid

Differential Revision: https://reviews.llvm.org/D99729

GitOrigin-RevId: f8f4d8f87ba4c1fbb18a4e7f4a5ea03a8b8ec061
1 file changed