Fixed a leak of ASTStructExtractors and also
made sure we don't keep around no-longer-valid
ASTTransformers.

<rdar://problem/15182379>

llvm-svn: 192333
diff --git a/lldb/source/Expression/ClangUserExpression.cpp b/lldb/source/Expression/ClangUserExpression.cpp
index 1e52ce2..c919653 100644
--- a/lldb/source/Expression/ClangUserExpression.cpp
+++ b/lldb/source/Expression/ClangUserExpression.cpp
@@ -95,15 +95,9 @@
 
 clang::ASTConsumer *
 ClangUserExpression::ASTTransformer (clang::ASTConsumer *passthrough)
-{    
-    ClangASTContext *clang_ast_context = m_target->GetScratchClangASTContext();
-    
-    if (!clang_ast_context)
-        return NULL;
-    
-    if (!m_result_synthesizer.get())
-        m_result_synthesizer.reset(new ASTResultSynthesizer(passthrough,
-                                                            *m_target));
+{
+    m_result_synthesizer.reset(new ASTResultSynthesizer(passthrough,
+                                                        *m_target));
     
     return m_result_synthesizer.get();
 }