Tint changes during Origin Trial

Changes for M95

New Features

• The size of an array can now be defined using a non-overridable module-scope constant
• The num_workgroups builtin is now supported.

Fixes

• Hex floats: now correctly errors when the magnitude is non-zero, and the exponent would cause overflow. tint:1150, tint:1166
• Identifers beginning with an underscore are now correctly rejected. tint:1179
• abs() fixed for unsigned integers on SPIR-V backend tint:1179