Utilizing gperf for TableGen

The newer code that TableGen produces is indeed lower however, MSVC
still throws the same error messages (and moreover, I don't think
they're fixing it anytime soon.. I'll try to re-open this issue to
them). Also, it seems that the new code produces an extraneous "if
(0);" statement before each of the else-if chains. Normally, compilers
would (and should) just optimize them away but it still counts agains
MSVC's ``nesting limit''.

Alright, try this:


I think the "if (0);" is there to make the code generator easier. The loop that produces the if-then statements now just has to generate the text:

  else if (...)
    IntrinsicID = ...;

instead of checking if it should emit the "else".


It finally compiles well with MSVC. Thanks!