'./configure --enable-fixed-point --with-fft=smallft' causes '-Wincompatible-pointer-types' in libspeexdsp/fftwrap.c

With ./configure --enable-fixed-point --with-fft=smallft, compilation of file libspeexdsp/fftwrap.c produces -Wincompatible-pointer-types diagnostics. This will prevent the project from being successfully built on Fedora 40 and other GNU/Linux distributions that use GCC 14 because, on GCC 14, -Wincompatible-pointer-types is treated as an error rather than a warning.

fftwrap.c: In function 'spx_fft_float':
fftwrap.c:384:19: error: passing argument 2 of 'spx_fft' from incompatible pointer type [-Wincompatible-pointer-types]
  384 |    spx_fft(table, _in, _out);
      |                   ^~~
      |                   |
      |                   spx_word16_t * {aka short int *}
fftwrap.c:98:34: note: expected 'float *' but argument is of type 'spx_word16_t *' {aka 'short int *'}
   98 | void spx_fft(void *table, float *in, float *out)
      |                           ~~~~~~~^~
fftwrap.c:384:24: error: passing argument 3 of 'spx_fft' from incompatible pointer type [-Wincompatible-pointer-types]
  384 |    spx_fft(table, _in, _out);
      |                        ^~~~
      |                        |
      |                        spx_word16_t * {aka short int *}
fftwrap.c:98:45: note: expected 'float *' but argument is of type 'spx_word16_t *' {aka 'short int *'}
   98 | void spx_fft(void *table, float *in, float *out)
      |                                      ~~~~~~~^~~
fftwrap.c: In function 'spx_ifft_float':
fftwrap.c:420:20: error: passing argument 2 of 'spx_ifft' from incompatible pointer type [-Wincompatible-pointer-types]
  420 |    spx_ifft(table, _in, _out);
      |                    ^~~
      |                    |
      |                    spx_word16_t * {aka short int *}
fftwrap.c:116:35: note: expected 'float *' but argument is of type 'spx_word16_t *' {aka 'short int *'}
  116 | void spx_ifft(void *table, float *in, float *out)
      |                            ~~~~~~~^~
fftwrap.c:420:25: error: passing argument 3 of 'spx_ifft' from incompatible pointer type [-Wincompatible-pointer-types]
  420 |    spx_ifft(table, _in, _out);
      |                         ^~~~
      |                         |
      |                         spx_word16_t * {aka short int *}
fftwrap.c:116:46: note: expected 'float *' but argument is of type 'spx_word16_t *' {aka 'short int *'}
  116 | void spx_ifft(void *table, float *in, float *out)
      |                                       ~~~~~~~^~~

To reproduce this issue:

Clone this repository and enter the directory containing the clone
Run ./autogen.sh
If gcc --version reports GCC 14 or above, run ./configure --enable-fixed-point --with-fft=smallft;

Otherwise, run CFLAGS="-Werror=incompatible-pointer-types" ./configure --enable-fixed-point --with-fft=smallft
Run make