[+0-all-args] PartialApply always takes parameters at +1. Use an ensurePlusOne to make sure we create a copy if we need to.

rdar://34222540

Author: gottesmm

lib/SILGen/SILGenPoly.cpp

@@ -2915,7 +2915,7 @@ static ManagedValue createThunk(SILGenFunction &SGF,
   SingleValueInstruction *thunkedFn =
     SGF.B.createPartialApply(loc, thunkValue,
                              SILType::getPrimitiveObjectType(substFnType),
-                             subs, fn.forward(SGF),
+                             subs, fn.ensurePlusOne(SGF, loc).forward(SGF),
                              SILType::getPrimitiveObjectType(expectedType));
   if (expectedType->isNoEscape()) {
     thunkedFn = SGF.B.createConvertFunction(loc, thunkedFn,

test/SILGen/guaranteed_normal_args.swift

@@ -29,6 +29,11 @@ struct Buffer {
 
 typealias AnyObject = Builtin.AnyObject
 
+protocol Protocol {
+  associatedtype AssocType
+  static func useInput(_ input: Builtin.Int32, into processInput: (AssocType) -> ())
+}
+
 ///////////
 // Tests //
 ///////////
@@ -86,3 +91,11 @@ struct StructContainingBridgeObject {
     rawValue = Builtin.reinterpretCast(swiftObj)
   }
 }
+
+struct ReabstractionThunkTest : Protocol {
+  typealias AssocType = Builtin.Int32
+
+  static func useInput(_ input: Builtin.Int32, into processInput: (AssocType) -> ()) {
+    processInput(input)
+  }
+}