PassManager: invalidate analysis if a pass forgot to do so.

If a pass forgot to call invalidateAnalysis but deleted some instructions, the pass-manager can fix this.

Currently following passes do not invalidate analysis when they change the SIL:
* LowerTupleAddrConstructor
* DestroyAddrHoisting
* MoveOnlyChecker
* PredictableDeadAllocationElimination

Ideally we should fix those passes. But with this addition in the pass-manager it's not strictly necessary.

Fixes a compiler crash.

Author: eeckstein

include/swift/SIL/SILModule.h

@@ -1056,6 +1056,10 @@ class SILModule {
   /// See scheduledForDeletion for details.
   void flushDeletedInsts();
 
+  bool hasInstructionsScheduledForDeletion() const {
+    return !scheduledForDeletion.empty();
+  }
+
   /// Looks up the llvm intrinsic ID and type for the builtin function.
   ///
   /// \returns Returns llvm::Intrinsic::not_intrinsic if the function is not an

lib/SILOptimizer/PassManager/PassManager.cpp

@@ -743,6 +743,11 @@ void SILPassManager::runPassOnFunction(unsigned TransIdx, SILFunction *F) {
 
       // Continue time measurement (including flushing deleted instructions).
       startTime = std::chrono::system_clock::now();
+    } else {
+      if (Mod->hasInstructionsScheduledForDeletion()) {
+        // Last chance for invalidating analysis if the pass forgot to call invalidateAnalysis.
+        invalidateAnalysis(F, SILAnalysis::InvalidationKind::FunctionBody);
+      }
     }
     Mod->flushDeletedInsts();
   }
@@ -915,6 +920,12 @@ void SILPassManager::runModulePass(unsigned TransIdx) {
   assert(analysesUnlocked() && "Expected all analyses to be unlocked!");
   SMT->run();
   assert(analysesUnlocked() && "Expected all analyses to be unlocked!");
+  
+  if (!CurrentPassHasInvalidated && Mod->hasInstructionsScheduledForDeletion()) {
+    // Last chance for invalidating analysis if the pass forgot to call invalidateAnalysis.
+    invalidateAllAnalysis();
+  }
+  
   Mod->flushDeletedInsts();
   swiftPassInvocation.finishedModulePassRun();