C library: Add framework that may (or may not) eventually support shared libraries.

include/dllfcn.h

@@ -41,6 +41,7 @@
  ****************************************************************************/
 
 #include <nuttx/config.h>
+#include <sys/types.h>
 
 /****************************************************************************
  * Pre-processor Definitons
@@ -200,6 +201,7 @@ extern "C"
  *   information will be available through dlerror().
  *
  * Reference: OpenGroup.org
+ *
  * ****************************************************************************/
 
 FAR void *dlopen(FAR const char *file, int mode);
@@ -232,7 +234,8 @@ FAR void *dlopen(FAR const char *file, int mode);
  *   information will be available through dlerror().
  *
  * Reference: OpenGroup.org
- *  ****************************************************************************/
+ *
+ ****************************************************************************/
 
 FAR void *dlsym(FAR void *handle, FAR const char *name);
 
@@ -279,7 +282,7 @@ FAR void *dlsym(FAR void *handle, FAR const char *name);
 int dlclose(FAR void *handle);
 
 /****************************************************************************
- * Name:
+ * Name: dlerror
  *
  * Description:
  *   dlerror() returns a null-terminated character string (with no trailing
@@ -296,7 +299,8 @@ int dlclose(FAR void *handle);
  * Returned Value:
  *
  * Reference: OpenGroup.org
- *  ****************************************************************************/
+ *
+ ****************************************************************************/
 
 FAR char *dlerror(void);