Fix Thread.Start while debugging bug on OSX.
The OSX exception logic is running on a separate thread from the one that the exception happened. The CatchHardwareExceptionHolder::IsEnabled used to check for h/w exception holders assumed it was running on the thread the exception/holders happened not the exception notification thread. Moved the h/w exception holder count to the CPalThread object instead of a TLS thread variable so the OSX exception code can check it given a CPalThread instance.
The main problem was that the stubmgr when creating a thread (for the start notification) put a breakpoint in ThePreStubPatch which is in the coreclr text section and because the h/w exception holder check was broken, it thought the breakpoint wasn't the debugger's and aborted the coreclr process. The other part of this fix is to put a h/w exception holder around the called to ThePreStubPatch in prestub.cpp.
The stubmgr's delegate invoke subclass used the wrong registers for Linux/OSX to read the "this" and parameter registers. Added the proper ifdefs and registers (ecx -> rdi, rdx -> rsi) for the Unix platforms.
On both Linux and OSX, the h/w exception holder check in the exception routing logic needed to check if the int3/trap is in DBG_DebugBreak so asserts always abort/core dump. Move DBG_DebugBreak to an assembly worker so the start/end address can be used for this check.
13 files changed: