Don't run misc-non-private-member-variables-in-classes check on LLVM.

[hokein]

Summary

The check adds too much nosie on LLVM codebase (especially running clangd
with clang-tidy enabled).

The check seems too aggresive, it will give warnings as long as a struct
has a method, e.g.

struct Foo {

int X;
void f() {};

};

[JonasToth]

it is very noisy (in other projects too) and i would prefer a different warning policy for that check as well (e.g. one warning per class, not for every field it warns against).

.clang-tidy

-Checks: '-*,clang-diagnostic-*,llvm-*,misc-*,-misc-unused-parameters,readability-identifier-naming'
+Checks: '-*,clang-diagnostic-*,llvm-*,misc-*,-misc-unused-parameters,-misc-non-private-member-variables-in-classes,readability-identifier-naming'
 CheckOptions:
   - key:             readability-identifier-naming.ClassCase
     value:           CamelCase
   - key:             readability-identifier-naming.EnumCase
     value:           CamelCase
   - key:             readability-identifier-naming.FunctionCase
     value:           camelBack
   - key:             readability-identifier-naming.MemberCase
     value:           CamelCase
   - key:             readability-identifier-naming.ParameterCase
     value:           CamelCase
   - key:             readability-identifier-naming.UnionCase
     value:           CamelCase
   - key:             readability-identifier-naming.VariableCase
     value:           CamelCase