Compilation warnings for x86_64

With 0075a5f10a2872415d1813252004f0d0c01e1a8d which is an x86_64 firmware - Running on the perf branch (https://github.com/rehosting/libnvram/pull/17) I see some warnings:

/igloo_static/libnvram/nvram.c:81:12: warning: value size does not match register
      size specified by the constraint and modifier [-Wasm-operand-widths]
    : "r" (fd), "r" (op), "i" (SYS_flock)  // Inputs
           ^
/igloo_static/libnvram/nvram.c:75:14: note: use constraint modifier "w"
    "mov x0, %1\n"        // Move fd to x0, the first argument for the system call
             ^~
             %w1
/igloo_static/libnvram/nvram.c:81:22: warning: value size does not match register
      size specified by the constraint and modifier [-Wasm-operand-widths]
    : "r" (fd), "r" (op), "i" (SYS_flock)  // Inputs
                     ^
/igloo_static/libnvram/nvram.c:76:14: note: use constraint modifier "w"
    "mov x1, %2\n"        // Move op to x1, the second argument for the system call
             ^~
             %w2
/igloo_static/libnvram/nvram.c:80:13: warning: value size does not match register
      size specified by the constraint and modifier [-Wasm-operand-widths]
    : "=r" (retval)       // Output
            ^
/igloo_static/libnvram/nvram.c:79:10: note: use constraint modifier "w"
    "mov %0, x0\n"        // Move the result from x0 to retval
         ^~
         %w0
3 warnings generated.

rehosting / libnvram

Compilation warnings for x86_64 #19