[LifetimeCompletion] Enable.

Complete all lifetimes during SILGenCleanup.

Author: nate-chandler

include/swift/AST/SILOptions.h

@@ -180,8 +180,8 @@ class SILOptions {
   /// If set to true, compile with the SIL Opaque Values enabled.
   bool EnableSILOpaqueValues = false;
 
-  /// Require linear OSSA lifetimes after SILGen
-  bool OSSACompleteLifetimes = false;
+  /// Introduce linear OSSA lifetimes after SILGen
+  bool OSSACompleteLifetimes = true;
 
   /// Verify linear OSSA lifetimes after SILGen
   bool OSSAVerifyComplete = false;

lib/DriverTool/sil_opt_main.cpp

@@ -231,9 +231,9 @@ struct SILOptOptions {
   EnableSILOpaqueValues = llvm::cl::opt<bool>("enable-sil-opaque-values",
                         llvm::cl::desc("Compile the module with sil-opaque-values enabled."));
 
-  llvm::cl::opt<bool>
-  EnableOSSACompleteLifetimes = llvm::cl::opt<bool>("enable-ossa-complete-lifetimes",
-                        llvm::cl::desc("Require linear OSSA lifetimes after SILGenCleanup."));
+  llvm::cl::opt<bool> EnableOSSACompleteLifetimes = llvm::cl::opt<bool>(
+      "enable-ossa-complete-lifetimes", llvm::cl::init(true),
+      llvm::cl::desc("Require linear OSSA lifetimes after SILGenCleanup."));
   llvm::cl::opt<bool>
   EnableOSSAVerifyComplete = llvm::cl::opt<bool>("enable-ossa-verify-complete",
                         llvm::cl::desc("Verify linear OSSA lifetimes after SILGenCleanup."));