Added logger flags, for selectively disabling categories of logging (cpu, apu, kernel). Need to make more log messages make use of these flags.

The "close window" keyboard hotkey (Guide-B) now toggles between loglevel -1 and the loglevel set in your config.
Added LoggerBatch class, which accumulates strings into the threads scratch buffer. This is only intended to be used for very high frequency debug logging. if it exhausts the thread buffer, it just silently stops.
Cleaned nearly 8 years of dust off of the pm4 packet disassembler code, now supports all packets that the command processor supports.
Added extremely verbose logging for gpu register writes. This is not compiled in outside of debug builds, requires LogLevel::Debug and log_guest_driven_gpu_register_written_values = true.
Added full logging of all PM4 packets in the cp. This is not compiled in outside of debug builds, requires LogLevel::Debug and disassemble_pm4.
Piggybacked an implementation of guest callstack backtraces using the stackpoints from enable_host_guest_stack_synchronization. If enable_host_guest_stack_synchronization = false, no backtraces can be obtained.
Added log_ringbuffer_kickoff_initiator_bts. when a thread updates the cp's read pointer, it dumps the backtrace of that thread
Changed the names of the gpu registers CALLBACK_ADDRESS and CALLBACK_CONTEXT to the correct names.
Added a note about CP_PROG_COUNTER
Added CP_RB_WPTR to the gpu register table
Added notes about CP_RB_CNTL and CP_RB_RPTR_ADDR. Both aren't necessary for HLE
Changed name of UNKNOWN_0E00 gpu register to TC_CNTL_STATUS. Games only seem to write 1 to it (L2 invalidate)

src/xenia/gpu/d3d12/d3d12_command_processor.cc

@@ -24,6 +24,7 @@
 #include "xenia/gpu/gpu_flags.h"
 #include "xenia/gpu/registers.h"
 #include "xenia/gpu/xenos.h"
+#include "xenia/gpu/packet_disassembler.h"
 #include "xenia/ui/d3d12/d3d12_presenter.h"
 #include "xenia/ui/d3d12/d3d12_util.h"
 
@@ -1816,6 +1817,7 @@ void D3D12CommandProcessor::WriteRegisterForceinline(uint32_t index,
 }
 // todo: bit-pack the bools and use bitarith to reduce branches
 void D3D12CommandProcessor::WriteRegister(uint32_t index, uint32_t value) {
+  LogRegisterSet(index, value);
   WriteRegisterForceinline(index, value);
 }
 
@@ -2073,7 +2075,7 @@ XE_FORCEINLINE void
 D3D12CommandProcessor::WriteRegisterRangeFromMem_WithKnownBound(
     uint32_t start_index, uint32_t* base, uint32_t num_registers) {
   uint32_t end = start_index + num_registers;
-
+  LogRegisterSets(start_index, base, num_registers);
   uint32_t current_index = start_index;
 
   auto get_end_before_qty = [&end, current_index](uint32_t regnum) {