Symphony ISA specs for use in stdlib

# `default.isa`
The stock game ISA. Production code must comply to this. Taken from `symphony_11_functions` in game version 2.1.330A

# `test.isa`
ISA with additional instructions. These additional instructions may be used in
the tests directory only. Some of these instructions require hardware changes.

## Labels in more instructions

`cmp`, `load`, and `store` instructions (but not `pload` and `pstore`) now also accept labels.

## `qcall %a(label)`
Performs a jump-and-link function call, with label size up to 32 bits.

_HARDWARE:_ Store PC+4 in the result register when in jump mode.

## `li %a(register) %b:U32(immediate | label)`
Loads an immediate up to 32 bits long

_HARDWARE:_ No requirements

## `halt%c(condition)`
Halts if `flags` matches the condition.

_HARDWARE:_ Halt if instruction bit 31 is set AND the condition block is true.

```
condition
""     1000
".all" 1000
".e"   0001
".ne"  1001
".b"   0010
".ae"  1010
".be"  0011
".a"   1011
".l"   0100
".ge"  1100
".le"  0101
".g"   1101
```