mongodb: Use llvm runtime when using clang
mongodb: Use llvm runtime when using clang

Fixes linker errors like
src/mongo/platform/overflow_arithmetic.h:63: error: undefined reference to '__mulodi4'
src/mongo/platform/overflow_arithmetic.h:63: error: undefined reference to '__mulodi4'
src/mongo/platform/overflow_arithmetic.h:63: error: undefined reference to '__mulodi4'
src/mongo/platform/overflow_arithmetic.h:63: error: undefined reference to '__mulodi4'

Signed-off-by: Khem Raj <729d64b6f67515e258459a5f6d20ec88b2caf8df@gmail.com>

kraj/meta-clang,kraj/meta-clang,kraj/meta-clang