STYLE: Replace integer literals which are cast to bool.

Finds and replaces integer literals which are cast to bool.

cd ${BLDDIR}
run-clang-tidy.py -extra-arg=-D__clang__ -checks=-*,modernize-use-bool-literals  -header-filter=.* -fix

CommandLineArguments.cxx

@@ -709,7 +709,7 @@ bool CommandLineArguments::PopulateVariable(
   if (cs->Callback) {
     if (!cs->Callback(cs->Argument, value, cs->CallData)) {
       this->Internals->LastArgument--;
-      return 0;
+      return false;
     }
   }
   CommandLineArguments_DEBUG("Set argument: " << cs->Argument << " to "
@@ -759,10 +759,10 @@ bool CommandLineArguments::PopulateVariable(
         std::cerr << "Got unknown variable type: \"" << cs->VariableType
                   << "\"" << std::endl;
         this->Internals->LastArgument--;
-        return 0;
+        return false;
     }
   }
-  return 1;
+  return true;
 }
 
 } // namespace KWSYS_NAMESPACE

Directory.cxx

@@ -204,7 +204,7 @@ bool Directory::Load(const std::string& name)
   DIR* dir = opendir(name.c_str());
 
   if (!dir) {
-    return 0;
+    return false;
   }
 
   for (kwsys_dirent* d = readdir(dir); d; d = readdir(dir)) {
@@ -212,7 +212,7 @@ bool Directory::Load(const std::string& name)
   }
   this->Internal->Path = name;
   closedir(dir);
-  return 1;
+  return true;
 }
 
 unsigned long Directory::GetNumberOfFilesInDirectory(const std::string& name)