The SourceRangeAstVisitor has custom logic for blocks ending with a
statement that has a continuation range. In these cases, the trailing
continuation is removed which makes the reported coverage ranges a bit
nicer.

throw Error('foo') consists of an ExpressionStatement, with a
Throw expression stored within the statement. The source range itself
is stored with the Throw, not the statement.

We now properly extract the correct AST node for trailing throw
statements.

R=jgruber@chromium.org, neis@chromium.org, yangguo@chromium.org

Bug: v8:8691
Change-Id: Ibcbab79fbe54719a8993045040349c863b139011
Reviewed-on: https://chromium-review.googlesource.com/c/1480632
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59936}