Some minor cleaning up (#1910).

Not only that, but it prevents some compilation errors on Windows using
Qt 5.12.0 LTS:
[4/19] Performing update step for 'developerDocumentationBuild'
Current branch master is up to date.
[5/19] Performing update step for 'userDocumentationBuild'
Current branch master is up to date.
[6/19] Building CXX object
src\plugins\miscellaneous\Compiler\CMakeFiles\Compiler_tests.dir\tests\t
ests.cpp.obj
FAILED:
src/plugins/miscellaneous/Compiler/CMakeFiles/Compiler_tests.dir/tests/t
ests.cpp.obj
D:/Programming/OpenCOR/build/clcachewrapper
C:\PROGRA~2\MICROS~2.0\VC\bin\amd64\cl.exe  /nologo /TP
@src\plugins\miscellaneous\Compiler\CMakeFiles\Compiler_tests.dir\tests\
tests.cpp.obj.rsp /showIncludes
/Fosrc\plugins\miscellaneous\Compiler\CMakeFiles\Compiler_tests.dir\test
s\tests.cpp.obj
/Fdsrc\plugins\miscellaneous\Compiler\CMakeFiles\Compiler_tests.dir\
/FS -c ..\src\plugins\miscellaneous\Compiler\tests\tests.cpp
C:\Program Files (x86)\Microsoft Visual Studio
14.0\VC\INCLUDE\bitset(101): error C2666: 'operator /': 11 overloads
have similar conversions
C:\Qt\5.12.0\msvc2015_64\include\QtGui/qvector4d.h(281): note: could be
'const QVector4D operator /(const QVector4D &,const QVector4D &)'
C:\Qt\5.12.0\msvc2015_64\include\QtGui/qvector4d.h(276): note: or
'const QVector4D operator /(const QVector4D &,float)'
C:\Qt\5.12.0\msvc2015_64\include\QtGui/qvector3d.h(281): note: or
'const QVector3D operator /(const QVector3D &,const QVector3D &)'
C:\Qt\5.12.0\msvc2015_64\include\QtGui/qvector3d.h(276): note: or
'const QVector3D operator /(const QVector3D &,float)'
C:\Qt\5.12.0\msvc2015_64\include\QtGui/qvector2d.h(256): note: or
'const QVector2D operator /(const QVector2D &,const QVector2D &)'
C:\Qt\5.12.0\msvc2015_64\include\QtGui/qvector2d.h(251): note: or
'const QVector2D operator /(const QVector2D &,float)'
C:\Qt\5.12.0\msvc2015_64\include\QtGui/qtransform.h(402): note: or
 'QTransform operator /(const QTransform &,qreal)'
C:\Qt\5.12.0\msvc2015_64\include\QtCore/qsize.h(364): note: or
'const QSizeF operator /(const QSizeF &,qreal)'
C:\Qt\5.12.0\msvc2015_64\include\QtCore/qsize.h(194): note: or
'const QSize operator /(const QSize &,qreal)'
c:\qt\5.12.0\msvc2015_64\include\qtcore\qmargins.h(427): note: or
'QMarginsF operator /(const QMarginsF &,qreal)'
c:\qt\5.12.0\msvc2015_64\include\qtcore\qmargins.h(213): note: or
'QMargins operator /(const QMargins &,qreal)'
c:\qt\5.12.0\msvc2015_64\include\qtcore\qmargins.h(207): note: or
'QMargins operator /(const QMargins &,int)'
C:\Qt\5.12.0\msvc2015_64\include\QtCore/qfloat16.h(205): note: or
'double operator /(int,qfloat16) noexcept'
C:\Qt\5.12.0\msvc2015_64\include\QtCore/qfloat16.h(205): note: or
'double operator /(qfloat16,int) noexcept'
C:\Qt\5.12.0\msvc2015_64\include\QtCore/qfloat16.h(195): note: or
'float operator /(float,qfloat16) noexcept'
C:\Qt\5.12.0\msvc2015_64\include\QtCore/qfloat16.h(195): note: or
'float operator /(qfloat16,float) noexcept'
C:\Qt\5.12.0\msvc2015_64\include\QtCore/qfloat16.h(194): note: or
'double operator /(double,qfloat16) noexcept'
C:\Qt\5.12.0\msvc2015_64\include\QtCore/qfloat16.h(194): note: or
'double operator /(qfloat16,double) noexcept'
C:\Qt\5.12.0\msvc2015_64\include\QtCore/qfloat16.h(193): note: or
'long double operator /(long double,qfloat16) noexcept'
C:\Qt\5.12.0\msvc2015_64\include\QtCore/qfloat16.h(193): note: or
'long double operator /(qfloat16,long double) noexcept'
C:\Qt\5.12.0\msvc2015_64\include\QtCore/qfloat16.h(176): note: or
'qfloat16 operator /(qfloat16,qfloat16) noexcept'
C:\Qt\5.12.0\msvc2015_64\include\QtCore/qpoint.h(402): note: or
'const QPointF operator /(const QPointF &,qreal)'
C:\Qt\5.12.0\msvc2015_64\include\QtCore/qpoint.h(206): note: or
'const QPoint operator /(const QPoint &,qreal)'
C:\Program Files (x86)\Microsoft Visual Studio
14.0\VC\INCLUDE\bitset(101): note: while trying to match the argument
list '(std::size_t, )'
C:\Program Files (x86)\Microsoft Visual Studio
14.0\VC\INCLUDE\bitset(100): note: while compiling class template
member function 'bool std::bitset<59>::_Subscript(std::size_t) const'
C:\Program Files (x86)\Microsoft Visual Studio
14.0\VC\INCLUDE\bitset(108): note: see reference to function template
instantiation 'bool std::bitset<59>::_Subscript(std::size_t) const'
being compiled
..\src\plugins\thirdParty\LLVMClang\ext\release\include\llvm/IR/Attribut
es.h(683): note: see reference to class template instantiation
'std::bitset<59>' being compiled
[7/19] Performing configure step for 'developerDocumentationBuild'
-- Configuring done
-- Generating done
-- Build files have been written to:
D:/Programming/OpenCOR/build/ext/Build/developerDocumentationBuild
[8/19] Performing configure step for 'userDocumentationBuild'
-- Configuring done
-- Generating done
-- Build files have been written to:
D:/Programming/OpenCOR/build/ext/Build/userDocumentationBuild
ninja: build stopped: subcommand failed.

D:\Programming\OpenCOR\build>

src/plugins/miscellaneous/Compiler/tests/tests.cpp

@@ -37,12 +37,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 //==============================================================================
 
-#include "llvmclangbegin.h"
-    #include "llvm/ExecutionEngine/ExecutionEngine.h"
-#include "llvmclangend.h"
-
-//==============================================================================
-
 void Tests::initTestCase()
 {
     // Create our compiler engine