Clang: Fix threading issue with QRegExp

exactMatch() is declared const, but is actually not. Replace with
QRegularExpression.

Change-Id: Ib9d9c091de1cd81d81671c19a76cada8777ff287
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/clangcodemodel/clangutils.cpp

@@ -44,7 +44,7 @@
 #include <QDir>
 #include <QFile>
 #include <QLoggingCategory>
-#include <QRegExp>
+#include <QRegularExpression>
 #include <QSet>
 #include <QString>
 
@@ -154,8 +154,9 @@ private:
         // We already provide a custom clang include path matching the used libclang version,
         // so better ignore the clang include paths from the system as this might lead to an
         // unfavorable order with regard to include_next.
-        static QRegExp clangIncludeDir(QLatin1String(".*/lib/clang/\\d+\\.\\d+(\\.\\d+)?/include"));
-        if (clangIncludeDir.exactMatch(path))
+        static QRegularExpression clangIncludeDir(
+                    QLatin1String("\\A.*/lib/clang/\\d+\\.\\d+(\\.\\d+)?/include\\z"));
+        if (clangIncludeDir.match(path).hasMatch())
             return true;
 
         return false;