Failed to compile on High Sierra

[tombburnell]

This failed to compile - also curious if this library supports writing mp3 tags at all?

deps/mpg123/test.target.mk:179: warning: overriding commands for target Release/test' deps/lame/test.target.mk:187: warning: ignoring old commands for target Release/test'
CC(target) Release/obj.target/mp3lame/deps/lame/libmp3lame/VbrTag.o
../deps/lame/libmp3lame/VbrTag.c:263:5: warning: shifting a negative signed value is undefined [-Wshift-negative-value]
SHIFT_IN_BITS_VALUE(buffer[0], 8u, 0xffu);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../deps/lame/libmp3lame/VbrTag.c:254:68: note: expanded from macro 'SHIFT_IN_BITS_VALUE'
#define SHIFT_IN_BITS_VALUE(x,n,v) ( x = (x << (n)) | ( (v) & ~(-1 << (n)) ) )
~~ ^
../deps/lame/libmp3lame/VbrTag.c:265:5: warning: shifting a negative signed value is undefined [-Wshift-negative-value]
SHIFT_IN_BITS_VALUE(buffer[1], 3u, 7);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../deps/lame/libmp3lame/VbrTag.c:254:68: note: expanded from macro 'SHIFT_IN_BITS_VALUE'
#define SHIFT_IN_BITS_VALUE(x,n,v) ( x = (x << (n)) | ( (v) & ~(-1 << (n)) ) )