Multiple bps - #175

This PR introduces support for multiple breakpoints at the same location. Below are the design choices I made during development to ensure alignment:

• Breakpoint Dictionary Enhancement:

  • The breakpoints dictionary now contains, for each key, a BreakpointList type similar to other custom types in libdebug. This supports the filter method, allowing filtering by any breakpoint attribute.

• Hardware Breakpoints on Specific Threads:

  • When you install a hardware breakpoint on a specific thread, it is installed only on that thread. While this behavior is not entirely consistent with software breakpoints internally in libdebug, it aligns with external behavior and allows the saving of precious hardware breakpoints.

• Process-Scoped Software Breakpoints:

  • Since software breakpoints must be installed process-scoped, when they are installed on a specific thread, they are ignored if hit by other threads internally by libdebug.

• Managing Multiple Hardware Breakpoints:

  • Multiple hardware breakpoints installed at the same position with identical conditions and lengths are managed internally, resulting in only one hardware breakpoint register being used. If they differ in any way, different registers are used. Again, I tried to save as many hw breakpoints as possible without making risky assumptions.

• Coexistence of Software and Hardware Breakpoints:

  • If a user installs both software and hardware breakpoints at the same location, both are installed within the process/thread. While we can optimize by converting all breakpoints to hardware for increased speed, software and hardware breakpoints may exhibit different behaviors that users might want to exploit.