With precise binary code coverage, the reported count is either 0 or 1.
We only report 1 the first time we collect coverage data after the
function has been executed.
Since we do not care about the accurate execution count, we can optimize
the function once it has been executed once.
Also change best effort coverage to be implicitly binary.
R=caseq@chromium.org, jgruber@chromium.org, pfeldman@chromium.org
BUG=v8:5808
Review-Url: https://codereview.chromium.org/2766573003
Cr-Commit-Position: refs/heads/master@{#44074}
Collect code coverage from the available invocation counts.
The granularity is at function level, and invocation counts may
be lost to GC.
Coverage::Collect returns a std::vector of Coverage::ScriptData.
Each ScriptData contains a script ID and a std::vector of
Coverage::RangeEntry.
Each RangeEntry consists of a end position and the invocation
count. The start position is implicit from the end position of
the previous RangeEntry, or 0 if it's the first RangeEntry.
R=jgruber@chromium.org
BUG=v8:5808
Review-Url: https://codereview.chromium.org/2689493002
Cr-Commit-Position: refs/heads/master@{#43072}
