Bump compiler plugins Clang baseline to 5.0.2

...as discussed at
<https://lists.freedesktop.org/archives/libreoffice/2018-November/081435.html>
"minutes of ESC call ..."

Change-Id: Ia053da171d59747984546f38e19da808825b4f79
Reviewed-on: https://gerrit.libreoffice.org/63832
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

compilerplugins/clang/constfields.cxx

@@ -393,10 +393,7 @@ void ConstFields::check(const FieldDecl* fieldDecl, const Expr* memberExpr)
             break;
         }
         else if (isa<CastExpr>(parent) || isa<MemberExpr>(parent) || isa<ParenExpr>(parent)
-                 || isa<ParenListExpr>(parent)
-#if CLANG_VERSION >= 40000
-                 || isa<ArrayInitLoopExpr>(parent)
-#endif
+                 || isa<ParenListExpr>(parent) || isa<ArrayInitLoopExpr>(parent)
                  || isa<ExprWithCleanups>(parent))
         {
             walkUp();