simpleperf: record kernel symbols in perf.data.

To better support kernel profiling, record kernel symbols in perf.data
when necessary. An option --no-dump-kernel-symbols is added in
record command to always avoid recording kernel symbols.
The way to handle all zero /proc/modules and /proc/kallsyms is
improved. Add Better support in finding symbols for kernel modules.

Bug: 27403614
Change-Id: I470151c54f8a45ad1c101c1b94490e33d7fd7485
22 files changed