Remove LLDB_DEFAULT_SHELL #define, and determine this at runtime.

Differential Revision: http://reviews.llvm.org/D5805
Reviewed by: Greg Clayton

llvm-svn: 220217
diff --git a/lldb/source/Target/Platform.cpp b/lldb/source/Target/Platform.cpp
index edad002..9ab338d 100644
--- a/lldb/source/Target/Platform.cpp
+++ b/lldb/source/Target/Platform.cpp
@@ -1063,10 +1063,14 @@
             const bool first_arg_is_full_shell_command = false;
             uint32_t num_resumes = GetResumeCountForLaunchInfo (launch_info);
             if (log)
+            {
+                const FileSpec &shell = launch_info.GetShell();
+                const char *shell_str = (shell) ? shell.GetPath().c_str() : "<null>";
                 log->Printf ("Platform::%s GetResumeCountForLaunchInfo() returned %" PRIu32 ", shell is '%s'",
                              __FUNCTION__,
                              num_resumes,
-                             launch_info.GetShell () ? launch_info.GetShell () : "<null>");
+                             shell_str);
+            }
 
             if (!launch_info.ConvertArgumentsForLaunchingInShell (error,
                                                                   is_localhost,