[clang] [clang-tools-extra] Reland: [clang] NFC: Clear some uses of MemberPointerType::getClass (PR #132317)

[Mike Hommey via cfe-commits]

glandium wrote:

This causes crashes:
```
1.	/builds/worker/checkouts/gecko/dom/media/webrtc/MediaEngineWebRTC.cpp:48:44: current parser token ')'
2.	/builds/worker/checkouts/gecko/dom/media/webrtc/MediaEngineWebRTC.cpp:31:1: parsing namespace 'mozilla'
3.	/builds/worker/checkouts/gecko/dom/media/webrtc/MediaEngineWebRTC.cpp:42:40: parsing function body 'mozilla::MediaEngineWebRTC::MediaEngineWebRTC'
4.	/builds/worker/checkouts/gecko/dom/media/webrtc/MediaEngineWebRTC.cpp:42:40: in compound statement ('{}')
 #0 0x00007f1beb652d08 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/tmp/llvm/obj-broken/bin/../lib/libLLVM.so.21.0git+0xe96d08)
 #1 0x00007f1beb65075e llvm::sys::RunSignalHandlers() (/tmp/llvm/obj-broken/bin/../lib/libLLVM.so.21.0git+0xe9475e)
 #2 0x00007f1beb6533b1 SignalHandler(int, siginfo_t*, void*) Signals.cpp:0:0
 #3 0x00007f1bea25b050 (/lib/x86_64-linux-gnu/libc.so.6+0x3c050)
 #4 0x00007f1bf5e57e31 addAssociatedClassesAndNamespaces((anonymous namespace)::AssociatedLookup&, clang::CXXRecordDecl*) SemaLookup.cpp:0:0
 #5 0x00007f1bf5e45f6a addAssociatedClassesAndNamespaces((anonymous namespace)::AssociatedLookup&, clang::QualType) SemaLookup.cpp:0:0
 #6 0x00007f1bf5e45c81 clang::Sema::FindAssociatedClassesAndNamespaces(clang::SourceLocation, llvm::ArrayRef<clang::Expr*>, llvm::SmallSetVector<clang::DeclContext*, 16u>&, llvm::SmallSetVector<clang::CXXRecordDecl*, 16u>&) (/tmp/llvm/obj-broken/bin/../lib/libclang-cpp.so.21.0git+0x1ad3c81)
```
I'm running cvise to reduce the source code that leads to this.

https://github.com/llvm/llvm-project/pull/132317