Extend code_typed to be able to debug constant prop
I'm currently debugging code that uses a lot of arrays with
dimensions in their type parameters. This type of code heavily
relies on constant propagation to lift dimensions from the value
domain into the type domain. Unfortunately, it's a bit hard to
discover what exactly causes inference to drop information from
constants, because there's no way to feed in constants for a
particular invocation using code_typed. This is a quick hack to
remidy that, by making `$`-interpolated expressions available
as constants to type inference, e.g.
```julia
julia> @code_typed 1+1
CodeInfo(
53 1 ─ %1 = (Base.add_int)(x, y)::Int64
└── return %1
) => Int64
julia> @code_typed $(1)+$(1)
CodeInfo(
53 1 ─ return 2
) => Int64
```
Additionally, this extends the same mechanism to apply to
get/setproperty!, even in the absence of `$` for the symbol
argument, reflecting their special casing inference.
