[hip] Fix host object creation from fatbin

[hliao]

Summary

• __hip_fatbin should a symbol in .hip_fatbin section.

[hliao]

Even there's no functionality change, the original one breaks the kernel extraction script, which is designed to find the .hip_fatbin section. That internal tool is still required to extract kernels from objects generated from RDC linking.

[ashi1]

Looks good to me.

clang/lib/Driver/ToolChains/HIP.cpp

void AMDGCN::Linker::constructGenerateObjFileFromHIPFatBinary(
 
   // Add MC directives to embed target binaries. We ensure that each
   // section and image is 16-byte aligned. This is not mandatory, but
   // increases the likelihood of data to be aligned with a cache block
   // in several main host machines.
   ObjStream << "#       HIP Object Generator\n";
   ObjStream << "# *** Automatically generated by Clang ***\n";
   ObjStream << "  .type __hip_fatbin,@object\n";
-  ObjStream << "  .section .hip_fatbin,\"aMS\",@progbits,1\n";
-  ObjStream << "  .data\n";
+  ObjStream << "  .section .hip_fatbin,\"a\",@progbits\n";
   ObjStream << "  .globl __hip_fatbin\n";
   ObjStream << "  .p2align " << llvm::Log2(llvm::Align(HIPCodeObjectAlign))
             << "\n";
   ObjStream << "__hip_fatbin:\n";
   ObjStream << "  .incbin \"" << BundleFile << "\"\n";
   ObjStream.flush();
 
   // Dump the contents of the temp object file gen if the user requested that.