Since we don't actually have an "if" instruction, this is a very common
pattern when iterating over instructions. This adds a helper function for
it to make things a little less painful.
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
These include functions for adding and removing various bits of IR and
helpers for iterating over all the sources and destinations of an
instruction. This is similar to ir.cpp.
v2: Jason Ekstrand <jason.ekstrand@intel.com>:
whitespace and automake fixes
