nv50/ir/nir: don't assert on !main

required for OpenCL

Signed-off-by: Karol Herbst <kherbst@redhat.com>
Reviewed-by: Pierre Moreau <pierre.morrow@free.fr>

src/gallium/drivers/nouveau/codegen/nv50_ir_from_nir.cpp

@@ -1556,8 +1556,6 @@ Converter::parseNIR()
 bool
 Converter::visit(nir_function *function)
 {
-   // we only support emiting the main function for now
-   assert(!strcmp(function->name, "main"));
    assert(function->impl);
 
    // usually the blocks will set everything up, but main is special