Fix compiler warnings

- celt/modes.c:430:14: warning: cast from 'const unsigned char *' to
  'opus_int16 *' increases required alignment from 1 to 2 [-Wcast-align]
- 'C[0][1]' may be used uninitialized [-Wmaybe-uninitialized]
- Unused variable/parameter
- Value stored is never read
- MSVC warnings about "possible loss of data" due to type conversions
- MSVC warning C4146: unary minus operator applied to unsigned type
- silk/NLSF_del_dec_quant.c:137:20: warning: array subscript is above
  array bounds [-Warray-bounds] (gcc -O3 false positive)
- src/mlp_train.h:39:20: warning: function declaration isn't a prototype
  [-Wstrict-prototypes]
- Remove SMALL_FOOTPRINT code from SSE 4.1 FIR implementation, matching
  the C implementation.

The clang -Wcast-align warnings with SSE intrinsics are a known
clang issue: https://llvm.org/bugs/show_bug.cgi?id=20670

1 files changed, 2 insertions, 2 deletions

diff --git a/src/mlp_train.h b/src/mlp_train.h
index 2786b40d..49404158 100644
--- a/src/mlp_train.h
+++ b/src/mlp_train.h
@@ -36,7 +36,7 @@ static inline double tansig_double(double x)
 {
     return 2./(1.+exp(-2.*x)) - 1.;
 }
-static inline void build_tansig_table()
+static inline void build_tansig_table(void)
 {
     int i;
     for (i=0;i<501;i++)
@@ -59,7 +59,7 @@ static inline double tansig_approx(double x)
     return y;
 }
 
-inline float randn(float sd)
+static inline float randn(float sd)
 {
    float U1, U2, S, x;
    do {