Update createMCObjectStreamer() to use new LLVM API (#156) (#157)

* Update createMCObjectStreamer() to use new LLVM API

Obsolete interfaces were removed via llvm-project's
f2ff298867d7733122e32eead5a8c524b09dfdb1

* Fix typo: LLVM_VERSION -> LLVM_VERSION_MAJOR

* Fix typo

[ROCm/ROCR-Runtime commit: ac1e6d59c2]

projects/rocr-runtime/libhsakmt/tests/kfdtest/src/Assemble.cpp

@@ -359,11 +359,18 @@ int Assembler::RunAssemble(const char* const AssemblySource) {
 	    return -1;
     }
 
+#if LLVM_VERSION_MAJOR > 20
+    std::unique_ptr<MCStreamer> Streamer(TheTarget->createMCObjectStreamer(
+        TheTriple, Ctx,
+	std::unique_ptr<MCAsmBackend>(MAB), MAB->createObjectWriter(*OS),
+        std::unique_ptr<MCCodeEmitter>(CE), *STI));
+#else
     std::unique_ptr<MCStreamer> Streamer(TheTarget->createMCObjectStreamer(
         TheTriple, Ctx,
         std::unique_ptr<MCAsmBackend>(MAB), MAB->createObjectWriter(*OS),
         std::unique_ptr<MCCodeEmitter>(CE), *STI, MCOptions.MCRelaxAll,
         MCOptions.MCIncrementalLinkerCompatible, /*DWARFMustBeAtTheEnd*/ false));
+#endif
 
     std::unique_ptr<MCAsmParser> Parser(
             createMCAsmParser(SrcMgr, Ctx, *Streamer, *MAI));