Inconsistency of parsing results of function expression with return type

[colinfang]

I noticed this when looking into #19122
Should we try to make them consistent so that the macro writer can have an easier life?

show(:(t(abc) = 3).args[2])

quote  # In[71], line 1:
    3
end


show(:(t(abc)::Int = 3).args[2])

3

This affects @inline, @noinline, etc.
They rely on pushmeta! which expects an Expr instead of Number for the function body.

function pushmeta!(ex::Expr, sym::Symbol, args::Any...)
    if isempty(args)
        tag = sym
    else
        tag = Expr(sym, args...)
    end

    inner = ex
    while inner.head == :macrocall
        inner = inner.args[end]::Expr
    end

    idx, exargs = findmeta(inner)
    if idx != 0
        push!(exargs[idx].args, tag)
    else
        body::Expr = inner.args[2]
        unshift!(body.args, Expr(:meta, tag))
    end
    ex
end

[ararslan]

Related to #19106?