message: Return 0 from cpuid for all subleaves of leaf 7
  This is necessary to support the cpufeatures crate
  Fixes
diff: @@ -12,6 +12,7 @@ pub(crate) fn codegen_cpuid_call<'tcx>(
  ) -> (Value, Value, Value, Value) {
  let leaf_0 = fx.bcx.create_block();
  let leaf_1 = fx.bcx.create_block();
  + let leaf_7 = fx.bcx.create_block();
  let leaf_8000_0000 = fx.bcx.create_block();
  let leaf_8000_0001 = fx.bcx.create_block();
  let unsupported_leaf = fx.bcx.create_block();
  @@ -25,6 +26,7 @@ pub(crate) fn codegen_cpuid_call<'tcx>(
  let mut switch = cranelift_frontend::Switch::new();
  switch.set_entry(0, leaf_0);
  switch.set_entry(1, leaf_1);
  + switch.set_entry(7, leaf_7);
  switch.set_entry(0x8000_0000, leaf_8000_0000);
  switch.set_entry(0x8000_0001, leaf_8000_0001);
  switch.emit(&mut fx.bcx, leaf, unsupported_leaf);
  @@ -43,6 +45,11 @@ pub(crate) fn codegen_cpuid_call<'tcx>(
  let edx_features = fx.bcx.ins().iconst(types::I32, 1 << 25 /* sse */ | 1 << 26 /* sse2 */);
  fx.bcx.ins().jump(dest, &[cpu_signature, additional_information, ecx_features, edx_features]);
  + fx.bcx.switch_to_block(leaf_7);
  + // This leaf technically has subleaves, but we just return zero for all subleaves.
  + let zero = fx.bcx.ins().iconst(types::I32, 0);
  + fx.bcx.ins().jump(dest, &[zero, zero, zero, zero]);
  +
  fx.bcx.switch_to_block(leaf_8000_0000);
  let extended_max_basic_leaf = fx.bcx.ins().iconst(types::I32, 0);
  let zero = fx.bcx.ins().iconst(types::I32, 0);
  