Debugger: Fix breakpoints swallowed or reported twice when resuming

The skip-first marker suppressed everything at the address you resume or
step from. That's needed for the pause, or you could never get off a
breakpoint, but it also dropped the log and hit count. So a log breakpoint
you'd stepped onto, or were parked on for some other reason, never logged
when execution moved on.

Now the skip only drops the pause, unless the breakpoint at that address is
the one that stopped us, which has already logged and counted this
execution. The check moves into the Exec* functions instead of being
repeated in the interpreter, IR interpreter and three JITs, where the
register breakpoint path only applied it to the pause and so logged twice
when stepping off a log+pause one. The marker gets an explicit valid flag,
since address 0 meant "none", and Core_Break() clears it.

Based on the earlier cleanup-skip-first branch, reduced to one marker plus
a flag. Checked over the WebSocket debugger on the interpreter, IR, x86 JIT
and JIT-IR: log breakpoints on a parked and a stepped-onto address each log
once, and stepping off a log+pause one doesn't report it again.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

Core/Core.cpp

@@ -687,6 +687,7 @@ void Core_Break(BreakReason reason, u32 relatedAddress, const BreakpointHit *hit
 		// later at an address nobody is waiting for anymore. Same as gdb dropping its step-resume
 		// breakpoint, or lldb discarding the thread plan, on any stop.
 		g_breakpoints.ClearTempBreakPoint();
+		g_breakpoints.ClearSkipFirst();
 
 		// Same reasoning for a cpu.runUntilTime deadline - it belonged to the run that just ended.
 		CoreTiming::SetBreakDeadlineUs(0);