force inlining of HUF_decodeSymbol*() functions
force inlining of HUF_decodeSymbol*() functions

which was not done properly by gcc 4.8
resulting in major performance difference.

ex :
zstd -b1 silesia.tar
before : dec 680 MB/s
after  : dec 710 MB/s  (without bmi2)
after  : dec 770 MB/s  (with DYNAMIC_BMI2)

Cyan4973/zstd,Cyan4973/zstd,Cyan4973/zstd,Cyan4973/zstd,Cyan4973/zstd