build: Create .la library for crc32c

Libtool will yell at you if you try to link a shared library against
static ones.

This change creates a libtool archive library for crc32c and allows a
shared library to be linked against it portably.

Also specify -static in both:

- ..._la_CXXFLAGS so that libtool will avoid building two versions of
  each object (one PIC, one non-PIC). We just need the one that is
  suitable for static linking.
- ..._la_LDFLAGS so that libtool will create a static library.

[META] This change is done in preparation for a future commit where we
       link the libbitcoinkernel library against this one.

0 files changed, 0 insertions, 0 deletions