Move FileSystem functions out of Host and into their own classes.

More specifically, this change can be summarized as follows:
1) Makes an lldbHostPosix library which contains code common to
   all posix platforms.
2) Creates Host/FileSystem.h which defines a common FileSystem
   interface.
3) Implements FileSystem.h in Host/windows and Host/posix.
4) Creates Host/FileCache.h, implemented in Host/common, which
   defines a class useful for storing handles to open files needed
   by the debugger.

Differential Revision: http://reviews.llvm.org/D4889

llvm-svn: 215775
diff --git a/lldb/source/Plugins/Process/POSIX/ProcessPOSIX.cpp b/lldb/source/Plugins/Process/POSIX/ProcessPOSIX.cpp
index a4cb087..2ce61e9 100644
--- a/lldb/source/Plugins/Process/POSIX/ProcessPOSIX.cpp
+++ b/lldb/source/Plugins/Process/POSIX/ProcessPOSIX.cpp
@@ -176,16 +176,14 @@
 }
 
 const char *
-ProcessPOSIX::GetFilePath(
-    const lldb_private::FileAction *file_action,
-    const char *default_path)
+ProcessPOSIX::GetFilePath(const lldb_private::FileAction *file_action, const char *default_path)
 {
     const char *pts_name = "/dev/pts/";
     const char *path = NULL;
 
     if (file_action)
     {
-        if (file_action->GetAction () == FileAction::eFileActionOpen)
+        if (file_action->GetAction() == FileAction::eFileActionOpen)
         {
             path = file_action->GetPath();
             // By default the stdio paths passed in will be pseudo-terminal