wasm - replace the WLL section with support to skip all unknown sections.

wasm - replace the WLL section with support to skip all unknown sections.

A section dedicated to WLL seems to be blocking consensus, so this patch offers
to remove it and replace it with support to skip all unknown sections. The WLL
section is relegated to an acknowledgment in a table with just the section
number and a link. The numbers are expected to be replaced by strings in future
and the namespace table might be managed by some community group in future.

This patch also moves to using a fixed width encoding for the size of these
sections as there has been some interest in back patching such sizes.

BUG=

[dougc, 2016-02-15 10:50:07]

Description was changed from

==========
wasm - replace the WLL section with support to skip all unknown sections.

A section dedicated to WLL seems to be blocking consensus, so this patch offers
to remove it and replace it with support to skip all unknown sections. The WLL
section is relegated to an acknowledgment in a table with just the section
number and a link. The numbers are expected to be replaced by strings in future
and the namespace table might be managed by some community group in future.

This patch also moves to using a fixed width encoding for the size of these
sections as there has been some interest in back patching such sizes.

BUG=
==========

to

==========
wasm - replace the WLL section with support to skip all unknown sections.

A section dedicated to WLL seems to be blocking consensus, so this patch offers
to remove it and replace it with support to skip all unknown sections. The WLL
section is relegated to an acknowledgment in a table with just the section
number and a link. The numbers are expected to be replaced by strings in future
and the namespace table might be managed by some community group in future.

This patch also moves to using a fixed width encoding for the size of these
sections as there has been some interest in back patching such sizes.

BUG=
==========

[dougc, 2016-02-15 10:50:07]

dtc-v8@scieneer.com changed reviewers:
+ ahaas@chromium.org