Use clock monotonic raw on Linux.

Because Linux kernel interfaces are fucking stupid.

client/TracyProfiler.cpp

@@ -84,11 +84,6 @@
 #  endif
 #endif
 
-#if defined TRACY_HW_TIMER && __ARM_ARCH >= 6 && !defined TARGET_OS_IOS
-#  include <signal.h>
-#  include <setjmp.h>
-#endif
-
 #if defined _WIN32 || defined __CYGWIN__
 #  include <lmcons.h>
 extern "C" typedef LONG (WINAPI *t_RtlGetVersion)( PRTL_OSVERSIONINFOW );
@@ -2585,9 +2580,6 @@ void Profiler::HandleDisconnect()
 void Profiler::CalibrateTimer()
 {
 #ifdef TRACY_HW_TIMER
-#  if !defined TARGET_OS_IOS && __ARM_ARCH >= 6
-    m_timerMul = 1.;
-#  else
     std::atomic_signal_fence( std::memory_order_acq_rel );
     const auto t0 = std::chrono::high_resolution_clock::now();
     const auto r0 = GetTime();
@@ -2602,7 +2594,6 @@ void Profiler::CalibrateTimer()
     const auto dr = r1 - r0;
 
     m_timerMul = double( dt ) / double( dr );
-#  endif
 #else
     m_timerMul = 1.;
 #endif