fix(debug): identify instruction breakpoints by resolved address to allow removal when instructionReference changes (#289678)

[maruthang]

What

Instruction breakpoints set from the Disassembly view could not be removed when the debug adapter returned a different instructionReference for the same memory location across disassemble requests.

Why

The Debug Adapter Protocol explicitly allows adapters to vary the instructionReference value returned for a given memory location between disassemble calls — only the resolved memory address is stable. The previous removeInstructionBreakpoints(reference, offset) lookup compared the (possibly new) reference+offset against the breakpoint's original reference+offset, so the match failed and the toggle-off click was a no-op.

Fixes #289678

How

• Extended IDebugService.removeInstructionBreakpoints / DebugService.removeInstructionBreakpoints / DebugModel.removeInstructionBreakpoints with an optional third parameter address?: bigint.
• When address is supplied, DebugModel matches on the stable resolved memory address already stored on InstructionBreakpoint, so a changed instructionReference no longer breaks removal.
• When address is omitted, the existing reference + offset matching path is preserved unchanged — all existing callers keep their current behavior.
• disassemblyView.ts now passes currentElement.element.address (the same address it already uses when adding the breakpoint), guaranteeing symmetric add/remove.

Test plan

• Added a new InstructionBreakpoint suite in src/vs/workbench/contrib/debug/test/common/debugModel.test.ts with 3 tests:
  1. Regression for Unable to remove instruction breakpoints in Disassembly view when instruction reference changes #289678 — removal succeeds when instructionReference has changed but address is stable.
  2. Back-compat — when address is not supplied, the legacy reference + offset matching still works.
  3. Targeted removal — supplying address only removes the breakpoint at that address, leaving others intact.
• npm run compile-check-ts-native passes cleanly.

[connor4312]

thanks!