...in order to remove some duplication.

Change-Id: Ie974b6ed9418967ad80b4604088b0e1c293b59d0
Reviewed-by: David Schulz <david.schulz@theqtcompany.com>

There are three cases that must be handled:

 1. Completion in C++ style comment
 2. Completion in first line of a C style comment
 3. Completion in non-first line of a C style comment

This change fixes case 1 + 2. Case 3 will be addressed in a follow-up
change, same goes for the duplication.

Task-number: QTCREATORBUG-15143
Change-Id: I449711f965ddcbbe6158870a8a5ae33218e0d238
Reviewed-by: David Schulz <david.schulz@theqtcompany.com>

* Update files in src/plugins

Change-Id: Ia5d77fad7d19d4bb3498e78661982f68729adb22
Reviewed-by: Tobias Hunger <tobias.hunger@theqtcompany.com>

This makes us independent of libclang crashes for completion.
Re-parsing for highlighting still happens in the Qt Creator process.

Run in verbose mode:
    qtc.clangcodemodel.ipc=true

Run tests:
    -test "ClangCodeModel"

Task-number: QTCREATORBUG-14108
Task-number: QTCREATORBUG-12819
Change-Id: Id3e95bd2afdb6508bbd1d35fddc69534a909b905
Reviewed-by: Marco Bubke <marco.bubke@theqtcompany.com>

As as side effect, this also brings some more pragma completions for the
builtin-in completion engine, e.g. "pragma once" or "pragma omp atomic".

Change-Id: If3ef22076c331c653b78a87cfff836c1da38c8fb
Reviewed-by: Erik Verbruggen <erik.verbruggen@theqtcompany.com>