Bug #19149091 5.5 BUILD BREAKS ON LINUX IF SUN DTRACE IS INSTALLED

  Add some code adapted from 5.6 to check for "real" DTrace. If found,
  and system is Linux, we simply set DTRACE to OFF. Otherwise no change.

  Build will still break if one tries to manually set DTRACE to ON.

cmake/dtrace.cmake

@@ -37,7 +37,15 @@ MACRO(CHECK_DTRACE)
  # On FreeBSD, dtrace does not handle userland tracing yet
  IF(DTRACE AND NOT CMAKE_SYSTEM_NAME MATCHES "FreeBSD"
      AND NOT BUGGY_GCC_NO_DTRACE_MODULES)
-   SET(ENABLE_DTRACE ON CACHE BOOL "Enable dtrace")
+   # 5.5 not able to do Sun dtrace on linux, just disable it
+   EXECUTE_PROCESS(
+     COMMAND ${DTRACE} -V
+     OUTPUT_VARIABLE out)
+   IF(out MATCHES "Sun D" AND CMAKE_SYSTEM_NAME MATCHES "Linux")
+     SET(ENABLE_DTRACE OFF CACHE BOOL "Sun DTrace on Linux not supported")
+   ELSE()
+     SET(ENABLE_DTRACE ON CACHE BOOL "Enable dtrace")
+   ENDIF()
  ENDIF()
  SET(HAVE_DTRACE ${ENABLE_DTRACE})
  IF(CMAKE_SYSTEM_NAME MATCHES "SunOS")