[VladimirMakaev]

The clang frontend types this as C const * in the const methods of C and as C * elsewhere.
RacerD and Starvation compared these types with their qualifiers when pairing accesses or locks of
two methods, missing races and deadlocks involving const methods:

#include <mutex>

class C {
  std::mutex m_;
  int x_;

 public:
  int get() const { return x_; } // Infer missed: LOCK_CONSISTENCY_VIOLATION
  void set(int v) {
    std::lock_guard<std::mutex> l(m_);
    x_ = v;
  }
};

RacerD now ignores the base type when grouping accesses, as AccessPath.compare does. Starvation
compares the root types of parameter-rooted locks across threads modulo qualifiers, so const C *
parameters also pair with C * ones.

Trade-off: two-instance deadlocks with const on one side only, such as x.copy_from(&y) against
y.copy_to(&x), are no longer reported, like the same code without const.

Test plan

New tests cpp/racerd/const_methods.cpp and cpp/starvation/const_methods.cpp. Of their _bad
cases, main reports only the two-instance deadlock FN_copy_from_bad, which is no longer
reported. All codetoanalyze tests pass.

[ngorogiannis]

Nice catch!

[VladimirMakaev]

Will reopen once current PR queue is cleared