perf supports a simple JIT interface to resolve symbols for dynamic code generated

by a JIT.

The JIT has to write a /tmp/perf-%d.map (%d = pid of process) file

This is a text file.

Each line has the following format, fields separated with spaces:

START SIZE symbolname

START and SIZE are hex numbers without 0x.

symbolname is the rest of the line, so it could contain special characters.

The ownership of the file has to match the process.