extractLibraries/extractFrameworks walked the merged root plus exactly
one namespace_decl level, so a #library reached through two or more
aliased imports never made it to the AOT link line or the JIT dlopen
list. Both walks now recurse over namespace_decl children.
Regression: examples/1617-modules-library-nested-namespace.sx binds
libpcap (not in the compiler's loaded images, so the JIT cannot mask
the miss via RTLD_DEFAULT) behind two aliased imports.