Enable precompiled headers for qtwebengine corev5.13.0-beta2

Chromium requires us to add a special config to enable precompiled
headers. Note this still depends additionally on that the corresponding
GN flag is also set.

Changes in 3rdparty:
9401dc18ce02 Add precompiled object files to qmake link output
8ba90427ae5e Improve the issue with long file names on windows

Change-Id: I6680232e17a5254d3ca53e5a40e6a15a6b7fc82d
Reviewed-by: Michal Klocek <michal.klocek@qt.io>

1 files changed, 0 insertions, 0 deletions

diff --git a/src/3rdparty b/src/3rdparty
-Subproject d8e950cba2f4e3625aa551715eb17a89a1a05be
+Subproject 8ba90427ae5edea70afbeb02df01f59c8fc366d