Resubmitting 240466 after fixing the linux test suite failures.

A few extras were fixed

- Symbol::GetAddress() now returns an Address object, not a reference. There were places where people were accessing the address of a symbol when the symbol's value wasn't an address symbol. On MacOSX, undefined symbols have a value zero and some places where using the symbol's address and getting an absolute address of zero (since an Address object with no section and an m_offset whose value isn't LLDB_INVALID_ADDRESS is considered an absolute address). So fixing this required some changes to make sure people were getting what they expected. 
- Since some places want to access the address as a reference, I added a few new functions to symbol:
    Address &Symbol::GetAddressRef();
    const Address &Symbol::GetAddressRef() const;

Linux test suite passes just fine now.

<rdar://problem/21494354>

llvm-svn: 240702
diff --git a/lldb/source/API/SBSymbol.cpp b/lldb/source/API/SBSymbol.cpp
index 12a3b31..246a455 100644
--- a/lldb/source/API/SBSymbol.cpp
+++ b/lldb/source/API/SBSymbol.cpp
@@ -137,10 +137,11 @@
         }
         if (m_opaque_ptr->ValueIsAddress())
         {
-            ModuleSP module_sp (m_opaque_ptr->GetAddress().GetModule());
+            const Address &symbol_addr = m_opaque_ptr->GetAddressRef();
+            ModuleSP module_sp = symbol_addr.GetModule();
             if (module_sp)
             {
-                AddressRange symbol_range (m_opaque_ptr->GetAddress(), m_opaque_ptr->GetByteSize());
+                AddressRange symbol_range (symbol_addr, m_opaque_ptr->GetByteSize());
                 const bool prefer_file_cache = false;
                 sb_instructions.SetDisassembler (Disassembler::DisassembleRange (module_sp->GetArchitecture (),
                                                                                  NULL,
@@ -172,7 +173,7 @@
     SBAddress addr;
     if (m_opaque_ptr && m_opaque_ptr->ValueIsAddress())
     {
-        addr.SetAddress (&m_opaque_ptr->GetAddress());
+        addr.SetAddress (&m_opaque_ptr->GetAddressRef());
     }
     return addr;
 }
@@ -186,7 +187,7 @@
         lldb::addr_t range_size = m_opaque_ptr->GetByteSize();
         if (range_size > 0)
         {
-            addr.SetAddress (&m_opaque_ptr->GetAddress());
+            addr.SetAddress (&m_opaque_ptr->GetAddressRef());
             addr->Slide (m_opaque_ptr->GetByteSize());
         }
     }