clang-format crashes on clang/test/Analysis/inline-plist.c

The minimum test case to reproduce the crash using the latest trunk version:
```
$ ls .clang-format
ls: .clang-format: No such file or directory
$ clang-format
int *p = ^int*(){ //
  return nullptr;
}();
Assertion failed: ((!TypeIsFinalized || T == Type) && "Please use overwriteFixedType to change a fixed type."), function setType, file FormatToken.h, line 351.
...
```