Reland "[gn] port 92b821f"

This reverts commit 344b534.
92b821f relanded in 0407248.

Author: nico

llvm/utils/gn/secondary/llvm/tools/llvm-exegesis/lib/BUILD.gn

@@ -8,7 +8,7 @@ static_library("lib") {
     "//llvm/lib/CodeGen",
     "//llvm/lib/CodeGen/GlobalISel",
     "//llvm/lib/ExecutionEngine",
-    "//llvm/lib/ExecutionEngine/MCJIT",
+    "//llvm/lib/ExecutionEngine/Orc",
     "//llvm/lib/ExecutionEngine/RuntimeDyld",
     "//llvm/lib/IR",
     "//llvm/lib/MC",