This cl adds 2 new utility function and adds one use of
these in the argument() function.
- getBlockId() finds a block by name and returns its ID
- getTypedMemberInfo() finds which block member matches
  a certain register index and returns the block member's
  packing information and type. If the register falls
  within a block member (as a sub-register of a matrix or
  an array), the base offset of the block member is
  returned, along with the register index, which will then
  be used within the argument() function to compute the
  final parameter index.

Change-Id: Ic0edcb3e6772cdb854301e3d0b400775e7ee72c0
Reviewed-on: https://swiftshader-review.googlesource.com/4682Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>
Tested-by: Nicolas Capens <capn@google.com>