Fix incorrect grammar in 'does not exists'

Change-Id: I790d9bbdfc170808ff66e70be0f81d1c292c0bcb
Reviewed-by: Eike Ziller <eike.ziller@qt.io>
Reviewed-by: Marco Bubke <marco.bubke@qt.io>

src/libs/clangsupport/filepathexceptions.h

@@ -43,7 +43,7 @@ class SourceNameIdDoesNotExists : std::exception
 public:
     const char *what() const noexcept override
     {
-        return "The source name id does not exists in the database!";
+        return "The source name id does not exist in the database!";
     }
 };
 
@@ -52,7 +52,7 @@ class DirectoryPathIdDoesNotExists : std::exception
 public:
     const char *what() const noexcept override
     {
-        return "The directory path id does not exists in the database!";
+        return "The directory path id does not exist in the database!";
     }
 };
 

src/libs/sqlite/sqlstatementbuilder.cpp

@@ -226,7 +226,7 @@ void SqlStatementBuilder::clearSqlStatement()
 void SqlStatementBuilder::checkIfPlaceHolderExists(Utils::SmallStringView name) const
 {
     if (name.size() < 2 || !name.startsWith('$') || !m_sqlTemplate.contains(name))
-        throwException("SqlStatementBuilder::bind: placeholder name does not exists!", name.data());
+        throwException("SqlStatementBuilder::bind: placeholder name does not exist!", name.data());
 }
 
 void SqlStatementBuilder::checkIfNoPlaceHoldersAynmoreExists() const

src/plugins/cppeditor/fileandtokenactions_test.cpp

@@ -320,7 +320,7 @@ class FollowSymbolUnderCursorTokenAction : public TestActionsTestCase::AbstractA
 {
 public:
     /// Follow symbol under cursor
-    /// Warning: May block if file does not exists (e.g. a not generated ui_* file).
+    /// Warning: May block if file does not exist (e.g. a not generated ui_* file).
     void run(CppEditorWidget *editorWidget);
 };
 
@@ -511,7 +511,7 @@ void CppEditorPlugin::test_moveTokenWiseThroughEveryFile()
     TestActionsTestCase(singleAction(ActionPointer(new NoOpTokenAction)));
 }
 
-/// May block if file does not exists (e.g. a not generated ui_* file).
+/// May block if file does not exist (e.g. a not generated ui_* file).
 void CppEditorPlugin::test_moveTokenWiseThroughEveryFileAndFollowSymbol()
 {
     TestActionsTestCase(singleAction(ActionPointer(new FollowSymbolUnderCursorTokenAction)));

src/tools/clangbackend/source/clangexceptions.cpp

@@ -58,7 +58,7 @@ DocumentDoesNotExistException::DocumentDoesNotExistException(const Utf8String &f
             + filePath
             + Utf8StringLiteral("' with the project part id '")
             + projectPartId
-            + Utf8StringLiteral("' does not exists!");
+            + Utf8StringLiteral("' does not exist!");
 }
 
 DocumentFileDoesNotExistException::DocumentFileDoesNotExistException(