clang-format: Improve formatting of operators forced to new lines.

Before:
  unsigned ContentSize =
      sizeof(int16_t) // DWARF ARange version number
      +
      sizeof(int32_t) // Offset of CU in the .debug_info section
      +
      sizeof(int8_t) // Pointer Size (in bytes)
      +
      sizeof(int8_t); // Segment Size (in bytes)

After:
  unsigned ContentSize =
      sizeof(int16_t)   // DWARF ARange version number
      + sizeof(int32_t) // Offset of CU in the .debug_info section
      + sizeof(int8_t)  // Pointer Size (in bytes)
      + sizeof(int8_t); // Segment Size (in bytes)

This fixes llvm.org/PR17687.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@194276 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Format/ContinuationIndenter.cpp b/lib/Format/ContinuationIndenter.cpp
index 63232be..1f6c869 100644
--- a/lib/Format/ContinuationIndenter.cpp
+++ b/lib/Format/ContinuationIndenter.cpp
@@ -439,10 +439,12 @@
   for (unsigned i = 0, e = State.Stack.size() - 1; i != e; ++i) {
     State.Stack[i].BreakBeforeParameter = true;
   }
-  const FormatToken *TokenBefore = Current.getPreviousNonComment();
-  if (TokenBefore && !TokenBefore->isOneOf(tok::comma, tok::semi) &&
-      TokenBefore->Type != TT_TemplateCloser &&
-      TokenBefore->Type != TT_BinaryOperator && !TokenBefore->opensScope())
+  if (PreviousNonComment &&
+      !PreviousNonComment->isOneOf(tok::comma, tok::semi) &&
+      PreviousNonComment->Type != TT_TemplateCloser &&
+      PreviousNonComment->Type != TT_BinaryOperator &&
+      Current.Type != TT_BinaryOperator && 
+      !PreviousNonComment->opensScope())
     State.Stack.back().BreakBeforeParameter = true;
 
   // If we break after { or the [ of an array initializer, we should also break