Legacy SwiftShader GL has a maximum framebuffer size of 8192 width
and height. SwiftShader Vulkan's maximum framebuffer size was 4096,
but this CL increases it to 8192. An issue was hit by using Chromium
with SwANGLE on an iMac Pro 5k screen, where the 4096 limit was
insufficient and causing a crash.

The viewport max dimensions and bounds range had to be adjusted
accordingly.

According to the spec:
"viewportBoundsRange[2] is the [minimum, maximum] range
 that the corners of a viewport must be contained in. This
 range must be at least [-2 × size, 2 × size - 1], where
 size = max(maxViewportDimensions[0], maxViewportDimensions[1])."

Bug: chromium:1209250
Change-Id: I0ef15ccf2433aea348fd7946319ffb3406174873
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/55008Tested-by: Alexis Hétu <sugoi@google.com>
Commit-Queue: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>