deno_core/
- rename core_isolate.rs to runtime.rs
- rename CoreIsolate to JsRuntime
- rename JSError to JsError
- rename JSStackFrame to JsStackFrame
cli/
- update references from deno_core::CoreIsolate to deno_core::JsRuntime
- rename deno_core::JSError to deno_core::JsError
- rename fmt_errors::JSError to fmt_errors::JsError