The new mangled name format is as follows:

The first character is a hex digit from 0 to F that encodes vector or
matrix size. For scalars, structs etc. the character is 0.

Then, if it's a struct, the mangled name continues with "{s", followed
by mangled names of fields, and ends with "}".

If it's an interface block, the mangled name continues with "{i",
followed by mangled names of fields, and ends with "}".

If it's anything else, the second alphabetic character encodes the
basic type. Characters are assigned to basic types in the enumeration
order.

If it's an array, the mangled name has a suffix [array_size].

This saves a few kilobytes from the binary size. The effect on symbol
lookup speed seems mostly marginal.

BUG=angleproject:2267
TEST=angle_unittests

Change-Id: I26e65dcb48c3478df9a719ffff9c15f2fd12e293
Reviewed-on: https://chromium-review.googlesource.com/945910
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>