message: Add at least the program name argument in order to get rustc tests a little further
diff: @@ -15,6 +15,7 @@ use rustc::ty::layout::Layout;
  use rustc::hir::def_id::DefId;
  use rustc::mir;
  +use syntax::ast::Mutability;
  use syntax::codemap::Span;
  use std::collections::{HashMap, BTreeMap};
  @@ -98,15 +99,21 @@ pub fn eval_main<'a, 'tcx: 'a>(
  dest,
  )?;
  - // Second argument (argc): 0
  + // Second argument (argc): 1
  let dest = ecx.eval_lvalue(&mir::Lvalue::Local(args.next().unwrap()))?;
  let ty = ecx.tcx.types.isize;
  - ecx.write_null(dest, ty)?;
  + ecx.write_primval(dest, PrimVal::Bytes(1), ty)?;
  - // Third argument (argv): 0
  + // FIXME: extract main source file path
  + // Third argument (argv): &[b"foo"]
  let dest = ecx.eval_lvalue(&mir::Lvalue::Local(args.next().unwrap()))?;
  let ty = ecx.tcx.mk_imm_ptr(ecx.tcx.mk_imm_ptr(ecx.tcx.types.u8));
  - ecx.write_null(dest, ty)?;
  + let foo = ecx.memory.allocate_cached(b"foo\0")?;
  + let ptr_size = ecx.memory.pointer_size();
  + let foo_ptr = ecx.memory.allocate(ptr_size * 1, ptr_size, MemoryKind::UninitializedStatic)?;
  + ecx.memory.write_primval(foo_ptr.into(), PrimVal::Ptr(foo.into()), ptr_size, false)?;
  + ecx.memory.mark_static_initalized(foo_ptr.alloc_id, Mutability::Immutable)?;
  + ecx.write_ptr(dest, foo_ptr.into(), ty)?;
  } else {
  ecx.push_stack_frame(
  main_instance,
  