Factor out makefile TBB detection, apply to all tools.

common/unix.mk

@@ -0,0 +1,16 @@
+# Common code needed by most Tracy Unix Makefiles.
+
+# Ensure LIBS is a simply-substituted variable, without changing its value.
+LIBS := $(LIBS)
+
+# Tracy does not use TBB directly, but the implementation of parallel algorithms
+# in some versions of libstdc++ depends on TBB. When it does, you must
+# explicitly link against -ltbb.
+#
+# Some distributions have pgk-config files for TBB, others don't.
+ifeq (0,$(shell pkg-config --libs tbb >/dev/null 2>&1; echo $$?))
+	LIBS += $(shell pkg-config --libs tbb)
+else ifeq (0,$(shell ld -ltbb -o /dev/null 2>/dev/null; echo $$?))
+	LIBS += -ltbb
+endif
+