Bug#1149534: mit-scheme: 12.1-7 fails to build on Ubuntu 26.10

[Barak A. Pearlmutter]

Okay, I'll look into the LTO deal, check if it is still an issue with
12.1-12 and with the latest upstream development snapshot. But fair
warning: if it's a hassle I'll just disable it, because it won't matter for
performance with the native back-ends, and with the bytecode back-end
you're already giving away ×20 and I doubt LTO will make a difference
because the code's fast-path is already pretty well tuned. Meantime I
suggest you disable LTO in Ubuntu for mit-scheme.