And simplify accordingly.

With hardware FPU, FI32 was only used within the mad decoder and
internally converted to FL32. With software FPU, FI32 did not work
properly as the S16N conversion was broken (at least since VLC1.1.0).

Apparently, mad generates sample values outside the [-1,+1] range, so
FL32 seems to be the most reasonable output format.

(On systems without hardware FPU, I would recommend disabling mad, and
using libavcodec for MPGA decoding.)

Previously, FPU detction was done before the variables for compiling (CC, CFLAGS, etc) were set. This broke on cross-compiles, because it was trying to use the default $(CC) to do the checks.

By doing the FPU detection after setting all the variables, FPU detection for cross-compiles works spectacularly.
Signed-off-by: Rafaël Carré <funman@videolan.org>

Close #6243

No functionnal changes */

Now audio codec frame size will not affect latency precision, at the
small cost of one memcpy per frame.
With the maximum number of OpenSLES buffers (255), we can have a precision
of 4ms with a buffer size of ~1 second.

We can access it with GetState

These objects do not depend on the audio format

To fix type aliasing, we need to know whether the data is float or integer,
or use only char pointers.

Also add support for FL64 and arbitrary lengths.