* change: runtimes with embedded cores (i.e. saved with :EXECUTABLE T)
don't print the startup banner, but behave as if --noinform was passed
as a command line argument. (thanks to Kevin Reid)
+ * new feature: added JOIN-THREAD (by NIIMI Satoshi)
* optimization: code using alien values with undeclared types is much faster.
* optimization: the compiler is now able to open code SEARCH in more cases.
* optimization: more compact typechecks on x86-64 (thanks to Lutz Euler)