Add new intcc and floatcc operand types for the immediate condition codes on
these instructions.
Add new IntCompare and FloatCompare instruction formats.
Add a generic match_enum() parser function that can match any identifier-like
enumerated operand kind that implements FromStr.
Define the icmp and fcmp instructions in case.py. Include documentation for the
condition codes with these two instructions.
We have a two-level type system: OperandKinds and ValueTypes. The value types
only apply to value operands, but there are many more kinds of operands:
immediate numbers, condition codes, basic block references, etc.
Add new immediate types for floating point and vector immediates.
Use new immediates to define the constant value instructions in meta.
Split the fconst instruction into two: f32const and f64const. This prevents
confusion about the interpretation of 64 immediate bits when generating an f32
constant.
Add an immvector ImmediateType. This immediate type is variable length, and
provides all the bits of a SIMD vector directly.
