[clang][ThreadSafety] Skip past implicit cast in translateAttrExpr

Ignore `ImplicitCastExpr` when building `AttrExp` for capability
attribute diagnostics.

Fixes: #92118.

Author: antoniofrighetto

clang/lib/Analysis/ThreadSafetyCommon.cpp

@@ -197,7 +197,7 @@ CapabilityExpr SExprBuilder::translateAttrExpr(const Expr *AttrExp,
   else if (const auto *UO = dyn_cast<UnaryOperator>(AttrExp)) {
     if (UO->getOpcode() == UO_LNot) {
       Neg = true;
-      AttrExp = UO->getSubExpr();
+      AttrExp = UO->getSubExpr()->IgnoreImplicit();
     }
   }
 

clang/test/SemaCXX/warn-thread-safety-analysis.cpp

@@ -5341,7 +5341,7 @@ void dispatch_log(const char *msg) __attribute__((requires_capability(!FlightCon
 void dispatch_log2(const char *msg) __attribute__((requires_capability(Logger))) {}
 
 void flight_control_entry(void) __attribute__((requires_capability(FlightControl))) {
-  dispatch_log("wrong"); /* expected-warning {{cannot call function 'dispatch_log' while mutex 'FlightControl' is held}} */
+  dispatch_log("wrong"); /* expected-warning {{cannot call function 'dispatch_log' while role 'FlightControl' is held}} */
   dispatch_log2("also wrong"); /* expected-warning {{calling function 'dispatch_log2' requires holding role 'Logger' exclusively}} */
 }