Add support for sized literals in the bytecode interpreter.

The bytecode interpreter only has branching instructions for
word-sized values. These are used for pattern matching.
Branching instructions for other types (e.g. Int16# or Word8#)
weren't needed, since unoptimized Core or STG never requires
branching on types like this.

It's now possible for optimized STG to reach the bytecode
generator (e.g. fat interface files or certain compiler flag
combinations), which requires dealing with various sized
literals in branches.

This patch improves support for generating bytecode from
optimized STG by adding the following new bytecode
instructions:

    TESTLT_I64
    TESTEQ_I64
    TESTLT_I32
    TESTEQ_I32
    TESTLT_I16
    TESTEQ_I16
    TESTLT_I8
    TESTEQ_I8
    TESTLT_W64
    TESTEQ_W64
    TESTLT_W32
    TESTEQ_W32
    TESTLT_W16
    TESTEQ_W16
    TESTLT_W8
    TESTEQ_W8

Fixes #21945