scr_cyc_types, scr_str_scan and scr_wtf8_lone were tentative definitions.
The macOS runtime build emits tentative definitions as COMMON symbols, and
Mach-O `ld -r` writes COMMON symbols back out as commons, which
-exported_symbols_list does not demote. Every runtime-localized library
archive therefore defined them next to its declared API, failing the
library-multi M1 and M7 symbol checks on macOS. Linux clang defaults to
-fno-common, so the same declarations were ordinary definitions there and
the checks passed.
Initialize the three globals explicitly, as scr_sa and
scr_stdio_write_hook already are, and add a runtime test that compiles
every runtime source with -fcommon in the plain and worker configurations
and expects no COMMON symbols, so a new tentative definition fails on
Linux too.
Chris Tate
9621b895ce