Change wrapped argument set-up to be closer to where it's needed: setting
up a top-level SFI, or initializing a ParseInfo from a top-level SFI.

This is a generally cleaner use of the interface, avoids splitting the
setting of the funciton syntax kind and wrapped arguments (including
checking script.is_wrapped() in two places for the same behaviour), plus
it avoids unnecessarily creating wrapped_argument handles for functions
inside a wrapped script.

As a drive-by, rename ParseInfo::SetFlagsFromScript to a clearer

ParseInfo::SetFlagsForFunctionInScript, to differentiate between flags
from a script for top-level vs. non-top-level.

Bug: v8:10314
Change-Id: Ibdaad957558c13a1528dcc3da1ba8f262f357e48
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2093509
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66643}