We now support a set of command line flags similar to "abseil"
benchmark thingy. I.e. to let people specify a subset of benchmarks or
run them longer/shorter as needed.
This commit also includes small, portable and very simple regexp
facility. It isn't good enough for some production use, but it is
plenty good for some testing uses or benchmark selection.
Instead of relying on gperftools-specific tc_XYZ functions for sized
deallocation and memalign we use standard C++ facilities. There are
also other minor improvements like mallocing larger buffers rather
than statically allocating them.
Aliaksei Kandratsenka