Consolidate UnixSignals setting/getting in Process.

See http://reviews.llvm.org/D5108 for details.

This change does the following:

* eliminates the Process::GetUnixSignals() virtual method and replaces with a fixed getter.
* replaces the Process UnixSignals storage with a shared pointer.
* adds a Process constructor variant that can be passed the UnixSignalsSP. When the constructor without the UnixSignalsSP is specified, the Host's default UnixSignals is used.
* adds a host-specific version of GetUnixSignals() that is used when we need the host's appropriate UnixSignals variant.
* replaces GetUnixSignals() overrides in PlatformElfCore, ProcessGDBRemote, ProcessFreeBSD and ProcessLinux with code that appropriately sets the Process::UnixSignals for the process.

This change also enables some future patches that will enable llgs to be used for local Linux debugging.

llvm-svn: 216748
diff --git a/lldb/source/Plugins/Process/POSIX/ProcessPOSIX.cpp b/lldb/source/Plugins/Process/POSIX/ProcessPOSIX.cpp
index 858d8ae..f340631 100644
--- a/lldb/source/Plugins/Process/POSIX/ProcessPOSIX.cpp
+++ b/lldb/source/Plugins/Process/POSIX/ProcessPOSIX.cpp
@@ -70,8 +70,8 @@
 //------------------------------------------------------------------------------
 // Constructors and destructors.
 
-ProcessPOSIX::ProcessPOSIX(Target& target, Listener &listener)
-    : Process(target, listener),
+ProcessPOSIX::ProcessPOSIX(Target& target, Listener &listener, UnixSignalsSP &unix_signals_sp)
+    : Process(target, listener, unix_signals_sp),
       m_byte_order(lldb::endian::InlHostByteOrder()),
       m_monitor(NULL),
       m_module(NULL),
@@ -878,12 +878,6 @@
     return status;
 }
 
-UnixSignals &
-ProcessPOSIX::GetUnixSignals()
-{
-    return m_signals;
-}
-
 //------------------------------------------------------------------------------
 // Utility functions.
 
diff --git a/lldb/source/Plugins/Process/POSIX/ProcessPOSIX.h b/lldb/source/Plugins/Process/POSIX/ProcessPOSIX.h
index a429b3c..033accf 100644
--- a/lldb/source/Plugins/Process/POSIX/ProcessPOSIX.h
+++ b/lldb/source/Plugins/Process/POSIX/ProcessPOSIX.h
@@ -18,7 +18,6 @@
 
 // Other libraries and framework includes
 #include "lldb/Target/Process.h"
-#include "lldb/Target/UnixSignals.h"
 #include "ProcessMessage.h"
 
 class ProcessMonitor;
@@ -33,7 +32,8 @@
     // Constructors and destructors
     //------------------------------------------------------------------
     ProcessPOSIX(lldb_private::Target& target,
-                 lldb_private::Listener &listener);
+                 lldb_private::Listener &listener,
+                 lldb_private::UnixSignalsSP &unix_signals_sp);
 
     virtual
     ~ProcessPOSIX();
@@ -154,9 +154,6 @@
     ProcessMonitor &
     GetMonitor() { assert(m_monitor); return *m_monitor; }
 
-    lldb_private::UnixSignals &
-    GetUnixSignals();
-
     const char *GetFilePath(const lldb_private::FileAction *file_action, const char *default_path);
 
     /// Stops all threads in the process.
@@ -192,9 +189,6 @@
     /// Drive any exit events to completion.
     bool m_exit_now;
 
-    /// OS-specific signal set.
-    lldb_private::UnixSignals m_signals;
-
     /// Returns true if the process has exited.
     bool HasExited();