#539 demangler does not demangle lambdas

[Ed Maste]

this symbol (from LLVM libunwind):

_ZZN9libunwind17LocalAddressSpace18findUnwindSectionsEjRNS_18UnwindInfoSectionsEENUlP12dl_phdr_infojPvE_8__invokeES4_jS5_

should demangle to:

libunwind::LocalAddressSpace::findUnwindSections(unsigned int, libunwind::UnwindInfoSections&)::{lambda(dl_phdr_info*, unsigned int, void*)#1}::__invoke(dl_phdr_info*, unsigned int, void*)

<name> ::= <unscoped-name>
<unscoped-name> ::= <unqualified-name>
<unqualified-name> ::= <unnamed-type-name>   
<unnamed-type-name> ::= <closure-type-name>
<closure-type-name> ::= Ul <lambda-sig> E [ <nonnegative number> ] _ 

[Ed Maste]

Ping?