[addr-move-function] Make sure to insert the debug_value for a reinit /after/ the reinit.

Otherwise, the memory lifetime verifier complains we are using the value while
it is not initialized.

I actually did this correctly in the single block impl. Just a small thinko.

Author: gottesmm

lib/SILOptimizer/Mandatory/MoveKillsCopyableAddressesChecker.cpp

@@ -1539,7 +1539,9 @@ bool DataflowState::cleanupAllDestroyAddr(
     // Make sure to create a new debug_value for the reinit value.
     if (addressDebugInst) {
       if (auto varInfo = addressDebugInst.getVarInfo()) {
-        SILBuilderWithScope reinitBuilder(*reinit);
+        // We need to always insert /after/ the reinit since the value will not
+        // be defined before the value.
+        SILBuilderWithScope reinitBuilder((*reinit)->getNextInstruction());
         reinitBuilder.setCurrentDebugScope(addressDebugInst->getDebugScope());
         reinitBuilder.createDebugValue(
             addressDebugInst.inst->getLoc(), address, *varInfo, false,

test/SILOptimizer/move_function_kills_copyable_addressonly_vars_crash.swift

@@ -0,0 +1,25 @@
+// RUN: %target-swift-frontend -enable-experimental-move-only %s -parse-stdlib -emit-sil -o /dev/null
+
+// REQUIRES: optimized_stdlib
+
+import Swift
+
+var booleanValue: Bool { true }
+
+public class Klass {
+    func doSomething() { print("something") }
+}
+
+
+// Make sure we put the dbg_info after the reinit, not before it. Otherwise this
+// test case crashes b/c we are using the value before it is reinited.
+public func copyableVarArgTestCCFlowReinitOutOfBlockTest(_ k: inout Klass) {
+    k.doSomething()
+    if booleanValue {
+        let m = _move(k)
+        m.doSomething()
+    }
+    k = Klass()
+    k.doSomething()
+}
+