malloc and exceptions

Those are the two remaining bits that will unlock a lot of functionality:

```julia
julia> exp.(oneArray(rand(ComplexF32, 2)))
ERROR: InvalidIRError: compiling kernel broadcast_kernel(oneAPI.oneKernelContext, oneDeviceVector{ComplexF32, 1}, Base.Broadcast.Broadcasted{Nothing, Tuple{Base.OneTo{Int64}}, typeof(exp), Tuple{Base.Broadcast.Extruded{oneDeviceVector{ComplexF32, 1}, Tuple{Bool}, Tuple{Int64}}}}, Int64) resulted in invalid LLVM IR
Reason: unsupported call to an unknown function (call to gpu_malloc)
Stacktrace:
[1] malloc
@ ~/Julia/pkg/GPUCompiler/src/runtime.jl:88
[2] macro expansion
@ ~/Julia/pkg/GPUCompiler/src/runtime.jl:185
[3] box
@ ~/Julia/pkg/GPUCompiler/src/runtime.jl:174
[4] box_float32
@ ~/Julia/pkg/GPUCompiler/src/runtime.jl:214
[5] sincos_domain_error
@ special/trig.jl:164
[6] sincos
@ special/trig.jl:181
[7] exp
@ complex.jl:655
[8] _broadcast_getindex_evalf
@ broadcast.jl:648
[9] _broadcast_getindex
@ broadcast.jl:621
[10] getindex
@ broadcast.jl:575
[11] broadcast_kernel
@ ~/Julia/depot/packages/GPUArrays/WV76E/src/host/broadcast.jl:62

```

Start with the failing ComplexF32 broadcast reproduction and read GPUCompiler/src/runtime.jl at the malloc and boxing locations shown in the stack trace. Trace how exp reaches special/trig.jl and complex.jl, then determine the required support for malloc and exceptions. Done means the example compiles and runs without the reported invalid LLVM IR error.

Written by the indexing model from the issue text.