Add support for LINE_COVERAGE (1/2)

This is the 1st part of the CL. It adds support to enable compilation
of line coverage instrumented binaries. For more details please refer
to the design doc: go/android-line-coverage-doc

Bug: b/147604881
Test: Code works successfully on Taimen devices
Change-Id: I07745c1438b611041ed032dd4b7788cb50130845