Implement Make handle_alloc_error default to panic (for no_std + liballoc)

Related: https://github.com/rust-lang/rust/issues/66741

Guarded with `#![feature(default_alloc_error_handler)]` a default
`alloc_error_handler` is called, if a custom allocator is used and no
other custom `#[alloc_error_handler]` is defined.

The panic message does not contain the size anymore, because it would
pull in the fmt machinery, which would blow up the code size
significantly.

compiler/rustc_codegen_llvm/src/lib.rs

@@ -95,8 +95,9 @@ impl ExtraBackendMethods for LlvmCodegenBackend {
         tcx: TyCtxt<'tcx>,
         mods: &mut ModuleLlvm,
         kind: AllocatorKind,
+        has_alloc_error_handler: bool,
     ) {
-        unsafe { allocator::codegen(tcx, mods, kind) }
+        unsafe { allocator::codegen(tcx, mods, kind, has_alloc_error_handler) }
     }
     fn compile_codegen_unit(
         &self,