simpleperf: Speed up disassembling many functions in a binary

report_html.py disassembles each function separately. This is slow
when there are thousands of functions, and we run llvm-objdump for each
of them. So change to disassemble the whole binary and parse the result
when needing to disassemble many functions in it.

Bug: 294296070
Test: run test.py
Test: run report_html.py disassembling libmonochrome_64.so
Change-Id: I9fa05dc5ce11ac95ba71a82d5ceecb919ea90630
3 files changed