Currently basic block kind of acts like a 'dumb struct' which makes things
a little more verbose to write (as opposed to keeping it all in one place,
I guess). It's also a little wonky conceptually, considering a block is
composed of instructions (i.e. 'contains' them).
So providing accessors that make it act more like a container can make working
with algorithms a little nicer. It also makes the API a little more
defined.
Ideally, the list would be only available through a function, but
currently, the pool allocator is exposed, which seems somewhat odd,
considering the block itself should manage its overall allocations
(with placement new, and regular new), rather than putting that
sanitizing directly on the IR emitter (it should just care about emission,
not block state). However, recontaining that can be followed up with,
as it's very trivial to do.
GetReturnFromRunCodeAddress is const qualified, so this can accept a const
pointer. This also allows for making the constructor accept a const
pointer as well.
Considering a HostLocInfo instance houses a std::vector, every time this
function is called can cause a potential heap allocation.
This can be somewhat unnecessary because this function is only used to query
for information we already have.
Considering this is used by several other internal query functions such as
IsRegisterOccupied, IsRegisterAllocated, and IsLastUse, this will result
in better codegen (returning an address is just 3 instructions excluding
the ret instruction for returning, meanwhile heap alloc can be 60+).
This also renames the function to have the same name as its non-const
counterpart, since overloading will just select the correct function
instead of putting that onus on the developer.
