Strings built by concatenating literals and pre-processor-defined
strings would lock the code extracting them for i18n forever.
This commit 'fixes' the issue by adding some support for these cases in
the `inbetween` regex snippet part of the 'extract string' complex regex
system, to avoid the lock.
The code has no way currently to extract the value of these defines
though, so they should not be used in translated strings.
NOTE: PR !122283 should do a propoer fix to these issues, by refactoring
the string building such that only actual strings pieces get processed
by the translation code.
a367cf664e