1. Refactored code to use HCC internal APIs rather than HCC copy APIs
2. Added hipMemcpyToSymbolAsync
3. Added test for hipMemcpyToSymbolAsync
4. Added new error hipErrorInvalidSymbol
Change-Id: I0e359b2d0ff5d682bbccdf9c2923e16b35e39497
[ROCm/clr commit: 0bf811b875]