SWDEV-1 - OpenCL binary substituion feature based on source program text hash matching.

This patch allows to substitute binary for the opencl program. It supposed to be used as:

1. Run the opencl program with -save-temps.

2. Open the cl temp and find the following text in the program header:
    Hash to override:
	Source: 0xd66bcfa20e69e605
	Source + clang options: 0x656a9dd8aedcbfb6

3. Create config file (ascii text) with a pair(s):

    <hash> <path_to_binary_to_substitute>

    where hash is the hex value from step 2 (without leading 0x), you can use either hash
    depending on what you're going to match:
	only the source text of the program or along with it's clang options.

4. Set the env variable AMD_OCL_SUBST_OBJFILE to the path of your config file.

5. Rerun the opencl program.

Change-Id: I977c80fe529ea14458194918c6ddfbe2de6a8857

rocclr/utils/flags.hpp

@@ -86,6 +86,8 @@ release(cstring, AMD_OCL_LINK_OPTIONS_APPEND, 0,                              \
         "Append clLinkProgram()'s options")                                   \
 release(cstring, AMD_OCL_SC_LIB, 0,                                           \
         "Set shader compiler shared library name or path")                    \
+debug(cstring, AMD_OCL_SUBST_OBJFILE, 0,                                      \
+        "Specify binary substitution config file for OpenCL")                 \
 debug(bool, AMD_OCL_ENABLE_MESSAGE_BOX, false,                                \
         "Enable the error dialog on Windows")                                 \
 release(size_t, GPU_PINNED_XFER_SIZE, 32,                                     \