[clang-format] Correct indentation for `[key] = value,` entries in C++ object initialisers

[jbcoe]

Summary

Do not use continuation indent for '[' in blocks in C# code.

[jbcoe]

Requires https://reviews.llvm.org/D75731 to be merged first.

[krasimir]

Looks good! I'll stamp this after https://reviews.llvm.org/D75731 gets merged and this rebased on top of it.

clang/lib/Format/ContinuationIndenter.cpp

1050

Please address the Pre-merge checks finding.

[jbcoe]

Format code.

[krasimir]

Thank you!

[dblaikie]

The mention of "C++ object initializers" in the commit message is a typo, yes? (it should be "C# object initializers" I assume?)

[jbcoe]

That's right David, this typo was fixed in a reverted and re-applied commit: https://reviews.llvm.org/D75856, https://reviews.llvm.org/D75747

clang/lib/Format/ContinuationIndenter.cpp

if (State.Stack.back().ColonPos > NextNonComment->ColumnWidth)
       return State.Stack.back().ColonPos - NextNonComment->ColumnWidth;
     return State.Stack.back().Indent;
   }
   if (NextNonComment->is(tok::colon) && NextNonComment->is(TT_ObjCMethodExpr))
     return State.Stack.back().ColonPos;
   if (NextNonComment->is(TT_ArraySubscriptLSquare)) {
     if (State.Stack.back().StartOfArraySubscripts != 0)
       return State.Stack.back().StartOfArraySubscripts;
+    else if (Style.isCSharp()) // C# allows `["key"] = value` inside object
+                               // initializers.
+      return State.Stack.back().Indent;
     return ContinuationIndent;
   }
 
   // This ensure that we correctly format ObjC methods calls without inputs,
   // i.e. where the last element isn't selector like: [callee method];
   if (NextNonComment->is(tok::identifier) && NextNonComment->FakeRParens == 0 &&
       NextNonComment->Next && NextNonComment->Next->is(TT_ObjCMethodExpr))
     return State.Stack.back().Indent;

clang/unittests/Format/FormatTestCSharp.cpp

Shape[] shapes = new[] { new Circle { Radius = 2.7281, Colour = Colours.Red },
 
   // Lambdas can be supplied as initialiser arguments.
   verifyFormat(R"(//
 private Transformer _transformer = new X.Y {
   Filler = (Shape shape) => { return new Transform.Fill(shape, RED); },
   Scaler = (Shape shape) => { return new Transform.Resize(shape, 0.1); },
 };)",
                Style);
+
+  // Dictionary initialisation.
+  verifyFormat(R"(//
+var myDict = new Dictionary<string, string> {
+  ["name"] = _donald,
+  ["age"] = Convert.ToString(DateTime.Today.Year - 1934),
+  ["type"] = _duck,
+};)",
+               Style);
 }
 
 TEST_F(FormatTestCSharp, CSharpNamedArguments) {
   FormatStyle Style = getGoogleStyle(FormatStyle::LK_CSharp);
 
   verifyFormat(R"(//
 PrintOrderDetails(orderNum: 31, productName: "Red Mug",
                   sellerName: "Gift Shop");)",