libFLAC : SSE optimisations.

Add new function:

    FLAC__lpc_compute_residual_from_qlp_coefficients_intrin_sse41()

and rewrite function:

    FLAC__lpc_compute_residual_from_qlp_coefficients_16_intrin_sse2()

Testing shows noticeable speed increase on Intel Core i3/5/7 (up to 30%
for -8 mode), AMD Athlon64, Phenom, Bulldozer/Piledriver, but no increase
or even very small speed decrease (~2% for -8 mode) on Intel Core2.

Patch-from: lvqcl <lvqcl.mail@gmail.com>

src/libFLAC/include/private/lpc.h

@@ -164,6 +164,7 @@ void FLAC__lpc_compute_residual_from_qlp_coefficients_16_intrin_sse2(const FLAC_
 void FLAC__lpc_compute_residual_from_qlp_coefficients_intrin_sse2(const FLAC__int32 *data, unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 residual[]);
 #    endif
 #    ifdef FLAC__SSE4_1_SUPPORTED
+void FLAC__lpc_compute_residual_from_qlp_coefficients_intrin_sse41(const FLAC__int32 *data, unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 residual[]);
 void FLAC__lpc_compute_residual_from_qlp_coefficients_wide_intrin_sse41(const FLAC__int32 *data, unsigned data_len, const FLAC__int32 qlp_coeff[], unsigned order, int lp_quantization, FLAC__int32 residual[]);
 #    endif
 #  endif