InternalModuleReadFile and InternalReadModuleJSON crash if directory named package.json.

[jdalton]

touch index.js
mkdir package.json
node ./

Will cause a hard crash

node[64237]: ../src/node_file.cc:505:void node::InternalModuleReadFile(const FunctionCallbackInfo<v8::Value> &): Assertion `(numchars) >= (0)' failed.
 1: node::Abort() [/Users/jdalton/.nvm/versions/node/v9.3.0/bin/node]
 2: node::InternalCallbackScope::~InternalCallbackScope() [/Users/jdalton/.nvm/versions/node/v9.3.0/bin/node]
 3: node::InternalModuleReadFile(v8::FunctionCallbackInfo<v8::Value> const&) [/Users/jdalton/.nvm/versions/node/v9.3.0/bin/node]
 4: v8::internal::FunctionCallbackArguments::Call(void (*)(v8::FunctionCallbackInfo<v8::Value> const&)) [/Users/jdalton/.nvm/versions/node/v9.3.0/bin/node]
 5: v8::internal::MaybeHandle<v8::internal::Object> v8::internal::(anonymous namespace)::HandleApiCallHelper<false>(v8::internal::Isolate*, v8::internal::Handle<v8::internal::HeapObject>, v8::internal::Handle<v8::internal::HeapObject>, v8::internal::Handle<v8::internal::FunctionTemplateInfo>, v8::internal::Handle<v8::internal::Object>, v8::internal::BuiltinArguments) [/Users/jdalton/.nvm/versions/node/v9.3.0/bin/node]
 6: v8::internal::Builtin_Impl_HandleApiCall(v8::internal::BuiltinArguments, v8::internal::Isolate*) [/Users/jdalton/.nvm/versions/node/v9.3.0/bin/node]
 7: 0x27c9edd042fd
 8: 0x27c9eddbd1e0
 9: 0x27c9eddbd1e0

[bnoordhuis]

Known issue, duplicate of #8307.