Support Symbols on the GPU

[vchuravy]

• Support Symbols
• fixup! Support Symbols
• Support passing Symbols to kernels

[vchuravy]

Error During Test at /var/lib/buildkite-agent/builds/amdgpu2-luraess-com/julialang/amdgpu-dot-jl/test/core/rocarray_base.jl:161
  Got exception outside of a @test
  MethodError: no method matching unsafe_wrap(::Type{AMDGPU.ROCArray}, ::Ptr{Symbol}, ::Int64)
  Closest candidates are:
    unsafe_wrap(::Type{<:AMDGPU.ROCArray}, ::Ptr{T}, ::Tuple{Vararg{var"#s85", N}} where var"#s85"<:Integer; own) where {T, N}
     @ AMDGPU /var/lib/buildkite-agent/builds/amdgpu2-luraess-com/julialang/amdgpu-dot-jl/src/array.jl:257
    unsafe_wrap(::Type{AMDGPU.ROCArray{T}}, ::Ptr, ::Any; kwargs...) where T
     @ AMDGPU /var/lib/buildkite-agent/builds/amdgpu2-luraess-com/julialang/amdgpu-dot-jl/src/array.jl:280
    unsafe_wrap(::Union{Type{Array}, Type{Array{T}}, Type{Vector{T}}}, ::Ptr{T}, ::Integer; own) where T
     @ Base pointer.jl:90
    ...