Move GridLaunch custom serializer

[kwu91]

This PR moved the grid_launch_parm custom serializer to a separate header file, grid_launch.hpp. A subclass called grid_launch_parm_cxx will contain the custom serializer. This header file, grid_launch.hpp is only used in the generated Wrapper file. The Wrapper file is changed to pass in the new class, grid_launch_parm_cxx to the functor. Running the benchmark with the new changes does not show a decrease in performance.

ROCK: dev/b0b2dee
ROCR: dev/de0d9b5

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Testing Time: 622.25s
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Failing Tests (4):
    CPPAMP :: Unit/HC/memcpy_symbol1.cpp
    CPPAMP :: Unit/HC/memcpy_symbol3.cpp
    CPPAMP :: Unit/HC/wg_size.cpp
    CPPAMP :: Unit/HSAIL/shfl_xor.cpp

  Expected Passes    : 664
  Expected Failures  : 25
  Unsupported Tests  : 10
  Unexpected Failures: 4

HIP-privatestaging: privatestaging/23c7882
HIP-Examples-privatestaging: privatestaging/23c7882

HIP Examples all passed.

HIP tests 2/35 failed:

15/35 Test #15: hipMemcpyAll.tst .......................***Failed  Required regular expression not found.Regex=[PASSED
23/35 Test #24: hipHostRegister.tst ....................***Exception: Other  0.10 sec