profiling: Add WITH_TIMING_COUNTS build option

This replaces the `ENABLE_TIMINGS` #define in `options.h`

Since we now support multiple back-ends for timing events, each back-end
is expected to be enabled with a `WITH_*` Makefile flag, and then the
JL_TIMING API is automatically enabled if any back-end is available.

Turning on multiple back-ends at the same time is also supported.

Make.inc

@@ -95,6 +95,9 @@ WITH_ITTAPI := 0
 # Enable Tracy support
 WITH_TRACY := 0
 
+# Enable Timing Counts support
+WITH_TIMING_COUNTS := 0
+
 # Prevent picking up $ARCH from the environment variables
 ARCH:=
 
@@ -743,6 +746,11 @@ JCFLAGS += -DUSE_TRACY -DTRACY_ENABLE -DTRACY_FIBERS
 LIBTRACYCLIENT:=-lTracyClient
 endif
 
+ifeq ($(WITH_TIMING_COUNTS), 1)
+JCXXFLAGS += -DUSE_TIMING_COUNTS
+JCFLAGS += -DUSE_TIMING_COUNTS
+endif
+
 # ===========================================================================
 
 # Select the cpu architecture to target, or automatically detects the user's compiler

src/options.h

@@ -78,9 +78,6 @@
 // OBJPROFILE counts objects by type
 // #define OBJPROFILE
 
-// Automatic Instrumenting Profiler
-#define ENABLE_TIMINGS
-
 
 // method dispatch profiling --------------------------------------------------
 

src/timing.h

@@ -20,6 +20,10 @@ void jl_destroy_timing(void) JL_NOTSAFEPOINT;
 #define HAVE_TIMING_SUPPORT
 #endif
 
+#if defined( USE_TRACY ) || defined( USE_TIMING_COUNTS )
+#define ENABLE_TIMINGS
+#endif
+
 #if !defined( ENABLE_TIMINGS ) || !defined( HAVE_TIMING_SUPPORT )
 
 #define JL_TIMING(subsystem, event)