SwiftCompilerSources: add Context.erase(instructionIncludingAllUsers:)

Author: eeckstein

SwiftCompilerSources/Sources/Optimizer/PassManager/Context.swift

@@ -79,16 +79,23 @@ extension MutatingContext {
     _bridged.eraseInstruction(instruction.bridged)
   }
 
-  func erase(instructionIncludingDebugUses inst: Instruction) {
+  func erase(instructionIncludingAllUsers inst: Instruction) {
+    if inst.isDeleted {
+      return
+    }
     for result in inst.results {
       for use in result.uses {
-        assert(use.instruction is DebugValueInst, "instruction to delete may only have debug_value uses")
-        erase(instruction: use.instruction)
+        erase(instructionIncludingAllUsers: use.instruction)
       }
     }
     erase(instruction: inst)
   }
 
+  func erase(instructionIncludingDebugUses inst: Instruction) {
+    precondition(inst.results.allSatisfy { $0.uses.ignoreDebugUses.isEmpty })
+    erase(instructionIncludingAllUsers: inst)
+  }
+
   func erase(block: BasicBlock) {
     _bridged.eraseBlock(block.bridged)
   }