Added default module launch api functionality

1. As in hipModuleLaunchKernel(..., kernelParams, nullptr); works with this commit
    2. Added headers AMDGPUPTNote.h, AMDGPURuntimeMetadata.h to do code object meta data parsing
    3. Changed CMake to look at llvm link libraries
    4. HIP developer should set env variable LLVM_HOME to remove link errors
    5. HIP depends on installed LLVM (not source, not build)
    6. Added sample to test out the feature
    7. Right now HCC does not support embedding metadata in code object. Use clang opencl
    8. Changed HIPCC to read LLVM_HOME env var
    9. New argument to CMake should be given -DLLVM_HOME=<where llvm 5.0 is installed>

Change-Id: Iba38194aa872d97cc2c90a8e5ff746c48055c868

samples/0_Intro/module_api/Makefile

@@ -5,14 +5,16 @@ endif
 HIPCC=$(HIP_PATH)/bin/hipcc
 HIP_PLATFORM=$(shell $(HIP_PATH)/bin/hipconfig --compiler)
 
-all: vcpy_kernel.code runKernel.hip.out
+all: vcpy_kernel.code runKernel.hip.out defaultDriver.hip.out
 
 runKernel.hip.out: runKernel.cpp
 	$(HIPCC) $(HIPCC_FLAGS) $< -o $@
 
+defaultDriver.hip.out: defaultDriver.cpp
+	$(HIPCC)  $(HIPCC_FLAGS) $< -o $@
+
 vcpy_kernel.code: vcpy_kernel.cpp
-	$(HIPCC) --genco $(GENCO_FLAGS) $^ -o $@
+	$(HIPCC)  --genco  $(GENCO_FLAGS) $^ -o $@
 
 clean:
 	rm -f *.code *.out
-