Don't duplicate embedded code objects (#1991)

If the code object is embedded in an already mapped file, and the
lifetime of the mapped file exceeds the lifetime of the executable,
we do not need to make a copy of the binary.

This allows the ROCR to present the code object URI as
file:///path/to/file#offset=X&size=Y.

[ROCm/hip commit: 9de5e90ab5]

projects/hip/src/hip_clang.cpp

@@ -89,9 +89,9 @@ __hipRegisterFatBinary(const void* data)
           reinterpret_cast<uintptr_t>(header) + desc->offset), desc->size};
       if (HIP_DUMP_CODE_OBJECT)
         __hipDumpCodeObject(image);
-      module->executable = hip_impl::get_program_state().load_executable(image.data(), image.size(),
-                                                                         module->executable,
-                                                                         agent);
+      module->executable = hip_impl::get_program_state().load_executable_no_copy(
+        reinterpret_cast<const char*>(header) + desc->offset, desc->size,
+        module->executable, agent);
 
       if (module->executable.handle) {
         modules->at(deviceId) = module;