GBA: Unhandled bkpt should be treated as an undefined exception

CHANGES

@@ -13,6 +13,7 @@ Emulation fixes:
  - GB Serialize: Add missing Pocket Cam state to savestates
  - GB SIO: Disabling SIO should cancel pending transfers (fixes mgba.io/i/2537)
  - GB Video: Implement DMG-style sprite ordering
+ - GBA: Unhandled bkpt should be treated as an undefined exception
  - GBA Audio: Fix sample timing drifting when changing sample interval
  - GBA Audio: Fix initial channel 3 wave RAM (fixes mgba.io/i/2947)
  - GBA BIOS: Fix clobbering registers with word-sized CpuSet

src/gba/gba.c

@@ -886,9 +886,6 @@ void GBAIllegal(struct ARMCore* cpu, uint32_t opcode) {
 
 void GBABreakpoint(struct ARMCore* cpu, int immediate) {
 	struct GBA* gba = (struct GBA*) cpu->master;
-	if (immediate >= CPU_COMPONENT_MAX) {
-		return;
-	}
 	switch (immediate) {
 #ifdef USE_DEBUGGERS
 	case CPU_COMPONENT_DEBUGGER:
@@ -899,6 +896,7 @@ void GBABreakpoint(struct ARMCore* cpu, int immediate) {
 				.pointId = -1
 			};
 			mDebuggerEnter(gba->debugger->d.p, DEBUGGER_ENTER_BREAKPOINT, &info);
+			return;
 		}
 		break;
 #endif
@@ -917,11 +915,13 @@ void GBABreakpoint(struct ARMCore* cpu, int immediate) {
 			if (hook) {
 				ARMRunFake(cpu, hook->patchedOpcode);
 			}
+			return;
 		}
 		break;
 	default:
 		break;
 	}
+	ARMRaiseUndefined(cpu);
 }
 
 void GBAFrameStarted(struct GBA* gba) {