Unable to parse argument destructuring syntax

[MasonProtter]

Looks like the internal parsing doesn't understand destructuring syntax:

julia> @macroexpand @btime (;a, b) = c
ERROR: MethodError: Cannot `convert` an object of type Expr to an object of type Symbol
The function `convert` exists, but no method is defined for this combination of argument types.

Closest candidates are:
  Symbol(::Any...)
   @ Base strings/basic.jl:229
  convert(::Type{T}, ::T) where T
   @ Base Base.jl:126

Stacktrace:
 [1] push!(a::Vector{Symbol}, item::Expr)
   @ Base ./array.jl:1249
 [2] _append!(a::Vector{Symbol}, ::Base.HasShape{1}, iter::Vector{Any})
   @ Base ./array.jl:1327
 [3] append!
   @ ./array.jl:1318 [inlined]
 [4] collectvars(ex::Expr, vars::Vector{Symbol})
   @ BenchmarkTools ~/.julia/packages/BenchmarkTools/QNsku/src/execution.jl:349
 [5] collectvars(ex::Expr)
   @ BenchmarkTools ~/.julia/packages/BenchmarkTools/QNsku/src/execution.jl:344
 [6] var"@benchmarkable"(__source__::LineNumberNode, __module__::Module, args::Vararg{Any})
   @ BenchmarkTools ~/.julia/packages/BenchmarkTools/QNsku/src/execution.jl:491
 [7] #macroexpand#74
   @ ./expr.jl:125 [inlined]
 [8] top-level scope
   @ REPL[4]:1