The types can differ for many opcodes where the right-hand side is a
constant, and this assert isn't that useful, so just remove the opcode
checks.

Bug chromium:805881

Change-Id: Ibcbda5123aaeaaf5753732d7cad4b5a3b331e963
Reviewed-on: https://swiftshader-review.googlesource.com/16730Tested-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>