[NFC] Move some lines earlier in code flow

To make the refactor of the methods `importFunctionParameterList` and
`importMethodParamsAndReturnType` easier in a later commit, move some
lines that were intermixed with the common code earlier in each of those
two methods. Even if some lines move earlier, there should be no
difference functionally.

Author: drodriguez

lib/ClangImporter/ImportType.cpp

@@ -2295,12 +2295,14 @@ ParameterList *ClangImporter::Implementation::importFunctionParameterList(
 
     ImportTypeKind importKind = getImportTypeKindForParam(param);
 
-    // Import the parameter type into Swift.
     ImportDiagnosticAdder paramAddDiag(*this, clangDecl, param->getLocation());
+
+    bool isInOut = false;
+    bool isParamTypeImplicitlyUnwrapped = false;
+
+    // Import the parameter type into Swift.
     auto attrs = getImportTypeAttrs(param, /*isParam=*/true);
     Type swiftParamTy;
-    bool isParamTypeImplicitlyUnwrapped = false;
-    bool isInOut = false;
 
     // Sometimes we import unavailable typedefs as enums. If that's the case,
     // use the enum, not the typedef here.
@@ -2902,13 +2904,20 @@ ImportedType ClangImporter::Implementation::importMethodParamsAndReturnType(
 
     bool paramIsCompletionHandler =
         asyncInfo && paramIndex == asyncInfo->completionHandlerParamIndex();
-
-    // Import the parameter type into Swift.
+    // Figure out if this is a completion handler parameter whose error
+    // parameter is used to indicate throwing.
+    Optional<unsigned> completionHandlerErrorParamIndex;
+    if (isAsync && paramIsCompletionHandler) {
+      completionHandlerErrorParamIndex =
+          asyncInfo->completionHandlerErrorParamIndex();
+    }
 
     // Check nullability of the parameter.
-    OptionalTypeKind optionalityOfParam
-        = getParamOptionality(param,
-                              !nonNullArgs.empty() && nonNullArgs[paramIndex]);
+    bool knownNonNull = !nonNullArgs.empty() && nonNullArgs[paramIndex];
+    OptionalTypeKind optionalityOfParam =
+        getParamOptionality(param, knownNonNull);
+
+    // Import the parameter type into Swift.
 
     bool allowNSUIntegerAsIntInParam = isFromSystemModule;
     if (allowNSUIntegerAsIntInParam) {
@@ -2922,11 +2931,13 @@ ImportedType ClangImporter::Implementation::importMethodParamsAndReturnType(
         allowNSUIntegerAsIntInParam = !nameContainsUnsigned(name);
     }
 
-    // Special case for NSDictionary's subscript.
     ImportTypeKind importKind = getImportTypeKindForParam(param);
     ImportDiagnosticAdder paramAddDiag(*this, clangDecl, param->getLocation());
-    Type swiftParamTy;
+
+    bool isInOut = false;
     bool paramIsIUO = false;
+
+    Type swiftParamTy;
     if (auto typedefType = dyn_cast<clang::TypedefType>(paramTy.getTypePtr())) {
       if (isUnavailableInSwift(typedefType->getDecl())) {
         if (auto clangEnum = findAnonymousEnumForTypedef(SwiftContext, typedefType)) {
@@ -2941,6 +2952,7 @@ ImportedType ClangImporter::Implementation::importMethodParamsAndReturnType(
       }
     }
 
+    // Special case for NSDictionary's subscript.
     if (kind == SpecialMethodKind::NSDictionarySubscriptGetter &&
         paramTy->isObjCIdType()) {
       // Not using `getImportTypeAttrs()` is unprincipled but OK for this hack.
@@ -2953,14 +2965,6 @@ ImportedType ClangImporter::Implementation::importMethodParamsAndReturnType(
 
       paramIsIUO = optionalityOfParam == OTK_ImplicitlyUnwrappedOptional;
     } else if (!swiftParamTy) {
-      // Figure out if this is a completion handler parameter whose error
-      // parameter is used to indicate throwing.
-      Optional<unsigned> completionHandlerErrorParamIndex;
-      if (isAsync && paramIsCompletionHandler) {
-        completionHandlerErrorParamIndex =
-            asyncInfo->completionHandlerErrorParamIndex();
-      }
-
       bool sendableByDefault = paramIsCompletionHandler &&
         SwiftContext.LangOpts.hasFeature(Feature::SendableCompletionHandlers);
 
@@ -3033,8 +3037,8 @@ ImportedType ClangImporter::Implementation::importMethodParamsAndReturnType(
     ++nameIndex;
 
     // Set up the parameter info
-    auto paramInfo = getParameterInfo(this, param, name, swiftParamTy,
-                                      /*isInOut=*/false, paramIsIUO);
+    auto paramInfo =
+        getParameterInfo(this, param, name, swiftParamTy, isInOut, paramIsIUO);
 
     // Determine whether we have a default argument.
     if (kind == SpecialMethodKind::Regular ||