ClangCodeModel: Change default set of warnings

... to "warnings from build system".
It seems appropriate to respect the project settings by default.

Change-Id: I397c252409a012f4663f3752c5c097fa0e658da4
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/cpptools/cppcodemodelsettings.cpp

@@ -37,7 +37,7 @@
 using namespace CppTools;
 
 static Utils::Id initialClangDiagnosticConfigId()
-{ return Constants::CPP_CLANG_DIAG_CONFIG_QUESTIONABLE; }
+{ return Constants::CPP_CLANG_DIAG_CONFIG_BUILDSYSTEM; }
 
 static CppCodeModelSettings::PCHUsage initialPchUsage()
 { return CppCodeModelSettings::PchUse_BuildSystem; }

src/plugins/cpptools/cpptoolsconstants.h

@@ -60,6 +60,7 @@ const char CPPTOOLS_SKIP_INDEXING_BIG_FILES[] = "SkipIndexingBigFiles";
 const char CPPTOOLS_INDEXER_FILE_SIZE_LIMIT[] = "IndexerFileSizeLimit";
 
 const char CPP_CLANG_DIAG_CONFIG_QUESTIONABLE[] = "Builtin.Questionable";
+const char CPP_CLANG_DIAG_CONFIG_BUILDSYSTEM[] = "Builtin.BuildSystem";
 
 const char CPP_CODE_STYLE_SETTINGS_ID[] = "A.Cpp.Code Style";
 const char CPP_CODE_STYLE_SETTINGS_NAME[] = QT_TRANSLATE_NOOP("CppTools", "Code Style");

src/plugins/cpptools/cpptoolsreuse.cpp

@@ -361,7 +361,7 @@ static void addBuiltinConfigs(ClangDiagnosticConfigsModel &model)
 
     // Warning flags from build system
     config = ClangDiagnosticConfig();
-    config.setId("Builtin.BuildSystem");
+    config.setId(Constants::CPP_CLANG_DIAG_CONFIG_BUILDSYSTEM);
     config.setDisplayName(QCoreApplication::translate("ClangDiagnosticConfigsModel",
                                                       "Build-system warnings"));
     config.setIsReadOnly(true);