style: use `cmStrCat` in some more locations

Source/CPack/IFW/cmCPackIFWGenerator.cxx

@@ -468,7 +468,7 @@ std::string cmCPackIFWGenerator::GetComponentInstallDirNameSuffix(
   const std::string suffix = "/data";
 
   if (this->componentPackageMethod == this->ONE_PACKAGE) {
-    return std::string(prefix + this->GetRootPackageName() + suffix);
+    return cmStrCat(prefix, this->GetRootPackageName(), suffix);
   }
 
   return prefix +

Source/CTest/cmCTestSubmitHandler.cxx

@@ -895,8 +895,7 @@ void cmCTestSubmitHandler::SelectParts(std::set<cmCTest::Part> const& parts)
   // Check whether each part is selected.
   for (cmCTest::Part p = cmCTest::PartStart; p != cmCTest::PartCount;
        p = cmCTest::Part(p + 1)) {
-    this->SubmitPart[p] =
-      (std::set<cmCTest::Part>::const_iterator(parts.find(p)) != parts.end());
+    this->SubmitPart[p] = parts.find(p) != parts.end();
   }
 }
 

Source/cmExtraEclipseCDT4Generator.cxx

@@ -737,7 +737,7 @@ void cmExtraEclipseCDT4Generator::CreateCProjectFile() const
     // exclude source directory from output search path
     // - only if not named the same as an output directory
     if (!cmSystemTools::FileIsDirectory(
-          std::string(this->HomeOutputDirectory + "/" + p))) {
+          cmStrCat(this->HomeOutputDirectory, '/', p))) {
       excludeFromOut += p + "/|";
     }
   }