data: indexer processes

* TaskBuildIndex starts seperate indexer processes and communicates via shared memory
* indexer processes get restarted if they fail
* indexer processes are killed when the app closes or crashes
* added utility class SharedMemory to allocate and access shared memory, providing basic data structures
* added SharedMemoryGarbageCollector for keeping track of running instances and cleaning up shared memory in case of a crash
* show errors for source files that crashed during indexing
* added basic exception handling to task scheduling
* added option to turn off processes and use threads in preferences, but still use shared memory

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src/lib_cxx/data/parser/cxx/ASTConsumer.cpp

@@ -1,4 +1,5 @@
 #include "data/parser/cxx/ASTConsumer.h"
+
 #include "data/parser/cxx/CxxAstVisitor.h"
 #include "data/parser/cxx/CxxVerboseAstVisitor.h"
 #include "settings/ApplicationSettings.h"
@@ -11,7 +12,9 @@ ASTConsumer::ASTConsumer(
 	std::shared_ptr<FilePathCache> canonicalFilePathCache
 )
 {
-	if (ApplicationSettings::getInstance()->getLoggingEnabled() && ApplicationSettings::getInstance()->getVerboseIndexerLoggingEnabled())
+	ApplicationSettings* appSettings = ApplicationSettings::getInstance().get();
+
+	if (appSettings->getLoggingEnabled() && appSettings->getVerboseIndexerLoggingEnabled())
 	{
 		m_visitor = std::make_shared<CxxVerboseAstVisitor>(context, preprocessor, client, fileRegister, canonicalFilePathCache);
 	}

src/lib_cxx/data/parser/cxx/CxxAstVisitor.cpp

@@ -299,7 +299,7 @@ bool CxxAstVisitor::TraverseTemplateTemplateParmDecl(clang::TemplateTemplateParm
 
 bool CxxAstVisitor::VisitTranslationUnitDecl(clang::TranslationUnitDecl *d)
 {
-	return !m_client->cancelOnFatalErrors() || !m_client->hasFatalErrors();
+	return true;
 }
 
 bool CxxAstVisitor::TraverseNestedNameSpecifierLoc(clang::NestedNameSpecifierLoc loc)

src/lib_cxx/data/parser/cxx/CxxParser.h

@@ -22,7 +22,6 @@ public:
 	void buildIndex(std::shared_ptr<IndexerCommandCxxManual> indexerCommand);
 	void buildIndex(const std::string& fileName, std::shared_ptr<TextAccess> fileContent);
 
-
 private:
 	std::vector<std::string> getCommandlineArgumentsEssential(
 		const std::vector<std::string>& compilerFlags,