CaseClause never made sense as an Expression; this CL allows us to
remove several UNREACHABLEs and slim down the representation of
CaseClause by removing its source position (which was only used
in prettyprinting).

The only real fallout of this change is that SourceRangeMap now
stores its keys as ZoneObject*, rather than AstNode*, but since
there's already compile time typechecking for inserting items
into the map this shouldn't cause any ill effects.

While modifying CaseClause, also removed the dead body_target()
accessor (and related member variable). Thus this CL overall
reduces the memory needed for each CaseClause by two words.

Bug: v8:6092
Change-Id: I0021c0590a69e29305c41ec6105c8824ae0cc25b
Reviewed-on: https://chromium-review.googlesource.com/639316Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Commit-Queue: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47722}

These counters handle cases in which the catch/finally block contains a jump
statement.

Bug: v8:6000
Change-Id: Ic83f11ee431edabe61f129c9abc3adc12a79c338
Reviewed-on: https://chromium-review.googlesource.com/586595Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46945}

The yield* statement when used in combination with async iterators is not
supported yet, as that is desugared into a more complex construct that doesn't
offer a good dedicated bytecode to attach the source range information yet.

Note that invocation counts of generator functions are incorrect as they count
each resumption as an individual call. See https://crbug.com/v8/6594.

Bug: v8:6000
Change-Id: I7ac7073473c9b64bb207cdbc4dab083ec1145656
Reviewed-on: https://chromium-review.googlesource.com/582690
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46890}

Bug: v8:6000
Change-Id: I8c068383300ba869a87f836504c84ea08fcff87e
Reviewed-on: https://chromium-review.googlesource.com/568307Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46675}

Both labeled blocks:

l0: { break l0; }

and blocks containing jump statements (break, return, continue) require a
continuation counter to correctly display coverage.

Bug: v8:6000
Change-Id: I3ae8ddd3d9f6c087622482b86014dd583b774b71
Reviewed-on: https://chromium-review.googlesource.com/568024Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46644}

This CL moves collected source range information out of AST nodes
and into a side table stored on ParseInfo. The side table is only 
created if block coverage is enabled, so there's almost no memory
overhead in the standard case.

Change-Id: I41871b8425ebbc6217d82d3ad26b5fc9e5d68ecb
Reviewed-on: https://chromium-review.googlesource.com/566808
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46590}