Add support for extended launch syntax. (#1530)

* Add support for extended launch syntax.

* Add unit test.

* Fix typo

* hipExtLaunchKernelGGL lives in hip_ext.h

Change-Id: Ice32dab0d43475fda65c6a910c11416871a8f2ff

* [dtest] remove redundant include from hipModuleGetGlobal dtest


[ROCm/hip commit: 69e74c3e96]

projects/hip/tests/src/runtimeApi/module/hipModuleGetGlobal.cpp

@@ -32,7 +32,6 @@ THE SOFTWARE.
 #include <iostream>
 #include <fstream>
 #include <vector>
-#include <hip/hip_ext.h>
 
 #define LEN 64
 #define SIZE LEN * sizeof(float)