Delete micro_bench.

Bionic benchmarks (bionic/benchmarks) has replaced micro_bench.

Micro bench of memset:

  micro_bench memset 8192 1

Bionic benchmarks equivalent:

  bionic-benchmarks --bionic_extra="BM_string_memset AT_ONEBUF_MANUAL_ALIGN_0_SIZE_8192"

Micro bench of memcpy:

  micro_bench memcpy 8192 1

Bionic benchmarks equivalent:

  bionic-benchmarks --bionic_extra="BM_string_memcpy AT_TWOBUF_MANUAL_ALIGN1_0_ALIGN2_0_SIZE_8192"

Note that you will need to run the 32 bit or 64 bit version of bionic
benchmarks depending on what version of the library routines you are
benchmarking.

Bug: 26928775

Test: Builds.
Change-Id: I463151e9ed3dc722c201aa07728ec0a48ebcf15e
3 files changed