[CSDiag] NFC: Remove obsolete trailing closure diagnostics

Author: xedin

lib/Sema/CSDiag.cpp

@@ -2021,32 +2021,6 @@ class ArgumentMatcher : public MatchCallArgumentListener {
     return true;
   }
 
-  bool trailingClosureMismatch(unsigned paramIdx, unsigned argIdx) override {
-    Expr *arg = ArgExpr;
-
-    auto tuple = dyn_cast<TupleExpr>(ArgExpr);
-    if (tuple)
-      arg = tuple->getElement(argIdx);
-
-    if (argIdx >= Parameters.size()) {
-      TC.diagnose(arg->getLoc(), diag::extra_trailing_closure_in_call)
-          .highlight(arg->getSourceRange());
-    } else {
-      auto &param = Parameters[paramIdx];
-      TC.diagnose(arg->getLoc(), diag::trailing_closure_bad_param,
-                  param.getPlainType())
-          .highlight(arg->getSourceRange());
-
-      auto candidate = CandidateInfo[0];
-      if (candidate.getDecl())
-        TC.diagnose(candidate.getDecl(), diag::decl_declared_here,
-                    candidate.getDecl()->getFullName());
-    }
-    Diagnosed = true;
-
-    return true;
-  }
-
   bool diagnose() {
     // Use matchCallArguments to determine how close the argument list is (in
     // shape) to the specified candidates parameters.  This ignores the