Remove gencpp_c11 for now (not using yet, maybe I'll do a truncated version)

Prepparing to explore Lottes's C-- more, also how crufty it looks in odin.

C/watl.v0.msvc.c

@@ -77,7 +77,7 @@ enum {
 	iter.cursor op iter.r.end;     \
 	++ iter.cursor
 
-#define def_span(type)                                                 \
+#define def_span(type)                                                \
 	        def_struct(tmpl(     Span,type)) { type begin; type end; }; \
 	typedef def_struct(tmpl(Iter_Span,type)) { tmpl(Span,type) r; type cursor; }