Building 'espresso' from llvm-test-suite revealed missing support
for duplex instructions with R_HEX_GOT_16_X.
You can remove the extraneous parentheses after return. Also, 0x0 should probably be just 0. Thus
return (0xC000 & insn) == 0;
LGTM, with the return (0xC000 & insn) == 0; change.
Fixed per review comments: removed superfluous parens around return expression, changed 0x0 to just 0.