[flang] Lower BIND(C) module variables (#78279)

Lower initialized BIND(C) module variable as regular module variable,
except that the fir.global symbol name is the binding label.

For uninitialized variables, add the common linkage so that C code may
define the variables. The standard does not provide a way to indicate
that a variable is defined in C, but there are use cases.

Beware that if the module file compiled object is added to a shared
library, the variable will become a regular global definition and may
override the C variable depending on the linking order.

0 files changed, 0 insertions, 0 deletions