WebAssembly control flow

WebAssembly control flow operators.

block
Creates a label that can later be branched out of with a br.
br
Branches to a loop or block.
call
Calls a function.
end
Can be used to end a block, loop, if, or else.
if...else
Executes a statement if the last item on the stack is true (1).
loop
Creates a label that can later be branched to with a br.
nop
Does nothing.
return
Returns from a function.
unreachable
Denotes a point in code that should not be reachable.