Previously, a user of the debug inspector API was supposed to use `rb_debug_inspector_backtrace_locations` to get an array of `Thread::Backtrace::Location`, and then used its index to get more information from `rb_debug_inspector _frame_binding_get(index)`, etc. However, `rb_debug_inspector_backtrace_locations` returned an array of backtraces excluding rescue/ensure frames. On the other hand, `rb_debug_inspector_frame_binding_get(index)` interprets index with rescue/ensure frames. This led to inconsistency of the index, and it was very difficult to correctly use the debug inspector API. This is a minimal fix for the issue by making `rb_debug_inspector_backtrace_locations` return a raw backtrace including rescue/ensure frames.