common-symbols.test.ts compiles every runtime source with the vendored
include paths only. scr_intl.c includes ICU's C API headers, which the
runtime pack build takes from the fetched ICU release, so on a host
without system ICU headers both of the test's compiles failed with
"'unicode/ubrk.h' file not found", and the aarch64-macos compile failed
on every host. The test now passes the same source/common and
source/i18n include paths for scr_intl.c, through icu-data.mjs's
ensureIcuSources.
Chris Tate
5a95e8a076