[SILOpt] Added -enable-copy-propagation flag.

The new flags sets the EnableCopyPropagation flag on the SILOpt[ion]s
class used to determine the behavior of sil-opt.

Author: nate-chandler

tools/sil-opt/SILOpt.cpp

@@ -122,6 +122,10 @@ static llvm::cl::opt<bool> EnableOSSAModules(
                    "this is disabled we do not serialize in OSSA "
                    "form when optimizing."));
 
+static llvm::cl::opt<bool> EnableCopyPropagation(
+    "enable-copy-propagation",
+    llvm::cl::desc("Enable the copy propagation pass."));
+
 namespace {
 enum class EnforceExclusivityMode {
   Unchecked, // static only
@@ -470,6 +474,7 @@ int main(int argc, char **argv) {
   SILOpts.EnableSpeculativeDevirtualization = EnableSpeculativeDevirtualization;
   SILOpts.IgnoreAlwaysInline = IgnoreAlwaysInline;
   SILOpts.EnableOSSAModules = EnableOSSAModules;
+  SILOpts.EnableCopyPropagation = EnableCopyPropagation;
 
   serialization::ExtendedValidationInfo extendedInfo;
   llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> FileBufOrErr =