[llvm-exegesis] Serializes instruction's operand in BenchmarkResult's key.

Summary: Follow up patch to https://reviews.llvm.org/D47764.

Reviewers: courbet

Subscribers: tschuett, llvm-commits

Differential Revision: https://reviews.llvm.org/D47785

llvm-svn: 334165
diff --git a/llvm/tools/llvm-exegesis/lib/BenchmarkRunner.cpp b/llvm/tools/llvm-exegesis/lib/BenchmarkRunner.cpp
index 0599c8e..1d8b34f 100644
--- a/llvm/tools/llvm-exegesis/lib/BenchmarkRunner.cpp
+++ b/llvm/tools/llvm-exegesis/lib/BenchmarkRunner.cpp
@@ -63,7 +63,9 @@
     InstrBenchmark.Error = "Empty snippet";
     return InstrBenchmark;
   }
-
+  for (const auto &MCInst : Snippet) {
+    InstrBenchmark.Key.Instructions.push_back(MCInst);
+  }
   InfoStream << "Snippet:\n";
   for (const auto &MCInst : Snippet) {
     DumpMCInst(MCRegisterInfo, MCInstrInfo, MCInst, InfoStream);