- Adding #include <stdbool.h> with protection in r17488 and r17504

seemed to be the right thing(tm), but broke the Sun Studio C++
   compiler under Linux (ticket 747).

   This patch should allow inclusion into C and C++ from other header
   files without problems.

This commit was SVN r17792.

The following SVN revision numbers were found above:
  r17488 --> open-mpi/ompi@d53131f261
  r17504 --> open-mpi/ompi@b22e8e7567

opal/threads/mutex.h

@@ -26,7 +26,11 @@
 
 #include "opal_config.h"
 
-#ifdef HAVE_STDBOOL_H
+/*
+ * Circumentvent problems in C++ compilers.
+ * For C++, we should not need the file, anyhow.
+ */
+#if defined(HAVE_STDBOOL_H) && !(defined(c_plusplus) || defined(__cplusplus))
 #include <stdbool.h>
 #endif
 

opal/util/output.h

@@ -67,7 +67,12 @@
 #ifdef HAVE_STDARG_H
 #include <stdarg.h>
 #endif
-#ifdef HAVE_STDBOOL_H
+
+/*
+ * For C++, we should not need the file, anyhow.
+ * Circumentvent problems in C++ compilers.
+ */
+#if defined(HAVE_STDBOOL_H) && !(defined(c_plusplus) || defined(__cplusplus))
 #include <stdbool.h>
 #endif