Fixes to unit tests for LC backend

[whchung]

This pull request consists fixes in runtime and unit tests for LC backend.

Failing HCC unit tests with HSAIL backend

CPPAMP :: Unit/HSAIL/shfl_xor.cpp

@scchan is working on getting this fixed

Failing HCC unit tests with LC backend

CPPAMP :: Unit/AmpMath/amp_math_erf_precise_math.cpp
CPPAMP :: Unit/AmpMath/amp_math_erfc_precise_math.cpp

Binaries for these 2 tests would run indefinitely. They pass if compiled with HSAIL backend.
Temporary let them fail immediately if compiled with LC backend.

CPPAMP :: Unit/AmpMath/amp_math_hypot_precise_math.cpp

Incorrect result with LC backend. It passes with HSAIL backend.

CPPAMP :: Unit/DynamicTileStatic/test11.cpp
CPPAMP :: Unit/DynamicTileStatic/test12.cpp
CPPAMP :: Unit/DynamicTileStatic/test13.cpp
CPPAMP :: Unit/DynamicTileStatic/test6.cpp
CPPAMP :: Unit/HC/get_group_segment_sizes.cpp
CPPAMP :: Unit/HC/memcpy_symbol1.cpp
CPPAMP :: Unit/HC/memcpy_symbol2.cpp
CPPAMP :: Unit/HC/memcpy_symbol3.cpp
CPPAMP :: Unit/HC/memcpy_symbol4.cpp

Tests related with dynamic LDS. Will get fix after getting dynamic LDS properly implemented. They all pass if compiled with HSAIL backend.

CPPAMP :: Unit/HSAIL/activelaneid.cpp
CPPAMP :: Unit/HSAIL/activelanepermute.cpp
CPPAMP :: Unit/HSAIL/shfl.cpp
CPPAMP :: Unit/HSAIL/shfl_down.cpp
CPPAMP :: Unit/HSAIL/shfl_up.cpp
CPPAMP :: Unit/HSAIL/shfl_xor.cpp
CPPAMP :: Unit/HSAIL/wavesize.cpp

Compile error with LC backend. Other than shfl_xor, they all pass if compiled with HSAIL backend. @scchan is working on fixing these now.

CPPAMP :: Unit/ParallelSTL/sort_carray.cpp
CPPAMP :: Unit/ParallelSTL/sort_stdarray.cpp
CPPAMP :: Unit/ParallelSTL/sort_stdvector.cpp
CPPAMP :: Unit/ParallelSTL/stablesort_carray.cpp
CPPAMP :: Unit/ParallelSTL/stablesort_stdarray.cpp
CPPAMP :: Unit/ParallelSTL/stablesort_stdvector.cpp

Compile error with LC backend. They all pass if compiled with HSAIL backend. Presumably codegen issue in LC backend.