Allow space after C-style cast in C# code

[MyDeveloperDay]

Thanks for the patch, really good to have others working on C# support. LGTM

clang/lib/Format/TokenAnnotator.cpp

bool isStartOfName(const FormatToken &Tok) {
     return (!IsPPKeyword &&
             PreviousNotConst->isOneOf(tok::identifier, tok::kw_auto)) ||
            PreviousNotConst->is(TT_PointerOrReference) ||
            PreviousNotConst->isSimpleTypeSpecifier();
   }
 
   /// Determine whether ')' is ending a cast.
   bool rParenEndsCast(const FormatToken &Tok) {
-    // C-style casts are only used in C++ and Java.
-    if (!Style.isCpp() && Style.Language != FormatStyle::LK_Java)
+    // C-style casts are only used in C++, C# and Java.
+    if (!Style.isCSharp() && !Style.isCpp() &&
+        Style.Language != FormatStyle::LK_Java)
       return false;
 
     // Empty parens aren't casts and there are no casts at the end of the line.
     if (Tok.Previous == Tok.MatchingParen || !Tok.Next || !Tok.MatchingParen)
       return false;
 
     FormatToken *LeftOfParens = Tok.MatchingParen->getPreviousNonComment();
     if (LeftOfParens) {

clang/unittests/Format/FormatTestCSharp.cpp

verifyFormat("foreach(var x in y) {\n"
                "}",
                Style);
   verifyFormat("switch(x) {}", Style);
   verifyFormat("do {\n"
                "} while(x);",
                Style);
 }
 
+TEST_F(FormatTestCSharp, CSharpSpaceAfterCStyleCast) {
+  FormatStyle Style = getGoogleStyle(FormatStyle::LK_CSharp);
+
+  verifyFormat("(int)x / y;", Style);
+
+  Style.SpaceAfterCStyleCast = true;
+  verifyFormat("(int) x / y;", Style);
+}
+
 } // namespace format
 } // end namespace clang