Debugger: Force GNU/Linux osabi when debugging elf on Windows

Coredump fails to open with multi-target gdb on Windows.

Change-Id: I66cea184a84539c9f56cc46d7eabadd7760ba649
Reviewed-by: hjk <hjk@theqtcompany.com>

src/plugins/debugger/gdb/coregdbadapter.cpp

@@ -204,6 +204,7 @@ void GdbCoreEngine::writeCoreChunk()
 void GdbCoreEngine::setupInferior()
 {
     CHECK_STATE(InferiorSetupRequested);
+    setLinuxOsAbi();
     // Do that first, otherwise no symbols are loaded.
     QFileInfo fi(m_executable);
     QByteArray path = fi.absoluteFilePath().toLocal8Bit();

src/plugins/debugger/gdb/gdbengine.cpp

@@ -1917,6 +1917,13 @@ void GdbEngine::handleGdbExit(const DebuggerResponse &response)
     }
 }
 
+void GdbEngine::setLinuxOsAbi()
+{
+    // In case GDB has multiple supported targets, the default osabi can be Cygwin.
+    if (HostOsInfo::isWindowsHost() && runParameters().toolChainAbi.binaryFormat() == Abi::ElfFormat)
+        runCommand({"set osabi GNU/Linux"});
+}
+
 void GdbEngine::detachDebugger()
 {
     CHECK_STATE(InferiorStopOk);

src/plugins/debugger/gdb/gdbengine.h

@@ -94,6 +94,7 @@ protected: ////////// Gdb Process Management //////////
     void startGdb(const QStringList &args = QStringList());
     void handleInferiorShutdown(const DebuggerResponse &response);
     void handleGdbExit(const DebuggerResponse &response);
+    void setLinuxOsAbi();
 
     void loadInitScript();
     void setEnvironmentVariables();

src/plugins/debugger/gdb/remotegdbserveradapter.cpp

@@ -162,6 +162,7 @@ void GdbRemoteServerEngine::uploadProcFinished()
 void GdbRemoteServerEngine::setupInferior()
 {
     QTC_ASSERT(state() == InferiorSetupRequested, qDebug() << state());
+    setLinuxOsAbi();
     const DebuggerRunParameters &rp = runParameters();
     QString executableFileName;
     if (!rp.inferior.executable.isEmpty()) {