Fix option parsing for repeated compiles online (#290)

diff --git a/lib/Compiler.cpp b/lib/Compiler.cpp
index 4587ea9..cb45de4 100644
--- a/lib/Compiler.cpp
+++ b/lib/Compiler.cpp
@@ -815,6 +815,7 @@
       "-simplifycfg-sink-common=false",
   };
 
+  llvm::cl::ResetAllOptionOccurrences();
   llvm::cl::ParseCommandLineOptions(llvmArgc, llvmArgv);
 
   llvm::SmallVector<const char *, 20> argv;