SILGen: Fix source location for the enum payload argument source

We should use the source location of the call site, and not the enum
element declaration, otherwise we emit incorrect debug info.

Fixes <rdar://problem/63067437>.

Author: slavapestov

lib/SILGen/SILGenApply.cpp

@@ -3818,7 +3818,7 @@ RValue CallEmission::applyEnumElementConstructor(SGFContext C) {
                                                   resultFnType.getParams(),
                                                   /*canonicalVararg*/ true);
     auto arg = RValue(SGF, argVals, payloadTy->getCanonicalType());
-    payload = ArgumentSource(element, std::move(arg));
+    payload = ArgumentSource(uncurriedLoc, std::move(arg));
     formalResultType = cast<FunctionType>(formalResultType).getResult();
     origFormalType = origFormalType.getFunctionResultType();
   } else {

test/SILGen/Inputs/enum_debuginfo_other.swift

@@ -0,0 +1,3 @@
+public enum MyEnum {
+  case hasPayload(argument: Any)
+}

test/SILGen/enum_debuginfo.swift

@@ -0,0 +1,7 @@
+// RUN: %target-swift-frontend -emit-silgen %S/Inputs/enum_debuginfo_other.swift -primary-file %s -module-name enum_debuginfo -g -Xllvm -sil-print-debuginfo | %FileCheck %s
+
+public func makeEnum() -> MyEnum {
+  return .hasPayload(argument: 123)
+}
+
+// CHECK-NOT: enum_debuginfo_other.swift