spinel

fix(codegen): #313 unbox poly-typed value to const char * at String#<< call site

Merge pull request #312 from matz/pr/bound-method-v2

feat(codegen): heap-allocated Method objects via synthetic Method class

fix(runtime): heap-use-after-free in sp_String_new(s) when s is a heap string

fix(codegen): #310 wrap elsif body in braces so prologue C decls stay in scope