https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html#Extended-Asm says
asm [volatile] ( AssemblerTemplate : [OutputOperands] [ : [InputOperands] [ : [Clobbers] ] ] )
which implies that Clobbers is optional even after the third colon, but
the gcc used for b2g_try_emulator_dep builds says
resample_neon.c: In function 'saturate_32bit_to_16bit':
resample_neon.c:50: error: expected string literal before ')' token
--HG--
extra : rebase_source : 6ca7768d5b30f67ff6827acc9a4fdc51a672bc1e
