[clang] [clang][analyzer] Simplify code of StreamChecker (NFC). (PR #79312)

[Ben Shi via cfe-commits]

benshi001 wrote:

I do not like too long lambda either. In my opinion lambda should be short/compact.

And I do not think the redundancy is serious, except the common part

```
  ProgramStateRef State = C.getState();
  SymbolRef StreamSym = getStreamArg(Desc, Call).getAsSymbol();
  if (!StreamSym)
    return;

  const CallExpr *CE = dyn_cast_or_null<CallExpr>(Call.getOriginExpr());
  if (!CE)
    return;

  const StreamState *OldSS = State->get<StreamMap>(StreamSym);
  if (!OldSS)
    return;

  assertStreamStateOpened(OldSS);
```

which appears in the beginning of most `evalXX` functions. And can we replace this piece with a macro ?

https://github.com/llvm/llvm-project/pull/79312