[Reproducers] Capture return values of functions returning by ptr/ref

For some reason I had convinced myself that functions returning by
pointer or reference do not require recording their result. However,
after further considering I don't see how that could work, at least not
with the current implementation. Interestingly enough, the reproducer
instrumentation already (mostly) accounts for this, though the
lldb-instr tool did not.

This patch adds the missing macros and updates the lldb-instr tool.

Differential revision: https://reviews.llvm.org/D60178

llvm-svn: 357639

lldb/source/API/SBSymbol.cpp

@@ -34,7 +34,7 @@ const SBSymbol &SBSymbol::operator=(const SBSymbol &rhs) {
                      SBSymbol, operator=,(const lldb::SBSymbol &), rhs);
 
   m_opaque_ptr = rhs.m_opaque_ptr;
-  return *this;
+  return LLDB_RECORD_RESULT(*this);
 }
 
 SBSymbol::~SBSymbol() { m_opaque_ptr = NULL; }