Fix broken ABI in qtwebengine libs between 5.8/5.9

Due to internal chromium 53 change in default allocator
qtwebengine 5.8 release exported globally operator new, new[],
delete and delete[] with Qt_5 'default' version.
The issue was spotted and fixed after official 5.8.0 release.
This causes ABI breakage since faulty released symbols are
missing in upcoming 5.9.0 release and the software compiled
against 5.8.0 will not work due to unresolved symbols at runtime.

Readd the symbols, however mark Qt_5 symbols version as
non-default, this way they are not picked up during link time,
but they still could be resolved during runtime.

Task-number: QTBUG-60565
Change-Id: I3320ac7785aea6b03443e8acd4b9d334e574d77f
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/core/api/core_api.pro

@@ -50,6 +50,10 @@ SOURCES = \
     qwebengineurlrequestjob.cpp \
     qwebengineurlschemehandler.cpp
 
+unix:!isEmpty(QMAKE_LFLAGS_VERSION_SCRIPT):!static {
+    SOURCES += qtbug-60565.cpp
+}
+
 msvc {
     # Create a list of object files that can be used as response file for the linker.
     # This is done to simulate -whole-archive on MSVC.

src/core/api/qtbug-60565.cpp

@@ -0,0 +1,121 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtWebEngine module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <new>
+#include <unistd.h>
+
+#if defined(__LP64__)
+#  define SIZE_T_MANGLING  "m"
+#else
+#  define SIZE_T_MANGLING  "j"
+#endif
+
+#define SHIM_ALIAS_SYMBOL(fn) __attribute__((weak, alias(#fn)))
+
+extern "C" {
+
+__asm__(".symver __ShimCppNew, _Znw" SIZE_T_MANGLING "@Qt_5");
+void* __ShimCppNew(size_t size)
+    SHIM_ALIAS_SYMBOL(ShimCppNew);
+
+__asm__(".symver __ShimDelete, _ZdlPv@Qt_5");
+void __ShimCppDelete(void* address)
+    SHIM_ALIAS_SYMBOL(ShimCppDelete);
+
+__asm__(".symver __ShimCppNewArray, _Zna" SIZE_T_MANGLING "@Qt_5");
+void* __ShimCppNewArray(size_t size)
+    SHIM_ALIAS_SYMBOL(ShimCppNewArray);
+
+__asm__(".symver __ShimCppDeleteArray, _ZdaPv@Qt_5");
+void __ShimCppDeleteArray(void* address)
+    SHIM_ALIAS_SYMBOL(ShimCppDeleteArray);
+
+__asm__(".symver __ShimCppNewNoThrow, _Znw" SIZE_T_MANGLING "RKSt9nothrow_t@Qt_5");
+void __ShimCppNewNoThrow(size_t size, const std::nothrow_t&) noexcept
+    SHIM_ALIAS_SYMBOL(ShimCppNew);
+
+__asm__(".symver __ShimCppNewArrayNoThrow, _Zna" SIZE_T_MANGLING "RKSt9nothrow_t@Qt_5");
+void __ShimCppNewArrayNoThrow(size_t size, const std::nothrow_t&) noexcept
+    SHIM_ALIAS_SYMBOL(ShimCppNewArray);
+
+__asm__(".symver __ShimCppDeleteNoThrow, _ZdaPvRKSt9nothrow_t@Qt_5");
+void __ShimCppDeleteNoThrow(void* address, const std::nothrow_t&) noexcept
+    SHIM_ALIAS_SYMBOL(ShimCppDelete);
+
+__asm__(".symver __ShimCppDeleteArrayNoThrow, _ZdaPvRSt9nothrow_t@Qt_5");
+void __ShimCppDeleteArrayNoThrow(void* address, const std::nothrow_t&) noexcept
+    SHIM_ALIAS_SYMBOL(ShimCppDeleteArray);
+
+static void* __shimCppNew(size_t size);
+static void* __shimCppNewArray(size_t size);
+static void __shimCppDelete(void *address);
+static void __shimCppDeleteArray(void *address);
+
+static void* ShimCppNew(size_t size) {
+    return __shimCppNew(size);
+}
+
+static void* ShimCppNewArray(size_t size) {
+    return __shimCppNewArray(size);
+}
+
+static void ShimCppDelete(void* address) {
+    __shimCppDelete(address);
+}
+
+static void ShimCppDeleteArray(void* address) {
+    __shimCppDeleteArray(address);
+}
+} // extern "C"
+
+static void* __shimCppNew(size_t size) {
+    return operator new(size);
+}
+
+static void* __shimCppNewArray(size_t size) {
+    return operator new[](size);
+}
+
+static void __shimCppDelete(void* address) {
+    operator delete(address);
+}
+
+static void __shimCppDeleteArray(void* address) {
+    operator delete[](address);
+}