[clang-format] Fix a crash caused by commit f03bf8c

Author: owenca

clang/lib/Format/TokenAnnotator.cpp

@@ -493,7 +493,7 @@ class AnnotatingParser {
             (CurrentToken->Next->is(tok::l_paren) ||
              (CurrentToken->Next->is(tok::l_square) &&
               (Line.MustBeDeclaration ||
-               PrevNonComment->isTypeName(LangOpts))))) {
+               (PrevNonComment && PrevNonComment->isTypeName(LangOpts)))))) {
           OpeningParen.setType(OpeningParen.Next->is(tok::caret)
                                    ? TT_ObjCBlockLParen
                                    : TT_FunctionTypeLParen);

clang/unittests/Format/FormatTest.cpp

@@ -13691,6 +13691,10 @@ TEST_F(FormatTest, FormatsArrays) {
       "                                  .aaaaaaaaaaaaaaaaaaaaaa();");
   verifyFormat("a[::b::c];");
 
+  verifyFormat("{\n"
+               "  (*a)[0] = 1;\n"
+               "}");
+
   verifyNoCrash("a[,Y?)]", getLLVMStyleWithColumns(10));
 
   FormatStyle NoColumnLimit = getLLVMStyleWithColumns(0);