clang-tidy: cheri: Allow modulus expressions in checkCastExpr

If the expression that is subject to a capability cast is a
modulus expression with a positive constant the capability
cast is ok because that expression cannot be a pointer.

Author: Christian Ehrhardt

clang-tools-extra/clang-tidy/cheri/CheriUtil.h

@@ -617,8 +617,9 @@ class Util {
 
       switch (Binop->getOpcode()) {
       case BO_And: {
+      case BO_Rem:
         /*
-         * If either side of the binary expression
+         * If either side of and "and" or "remainder" expression
          * is a positive constant this is ok.
          */
         if (Clhs && Clhs->sge(0))