Msys is unable to convert unix style absolute paths to windows style
paths when combined with certain multichar MSVC options such as
-Fo<file>. We used to work around this issue by passing them as two
separate parameters separated by a space to c99wrap, which then mapped
them back to the actual parameter format that MSVC uses.

The only paths that actually are an issue are absolute unix style
paths, and the only place such absolute paths are used with the output
arguments (-Fo, -Fe, -Fi, -out:) are for the temp files within configure.

By setting TMPDIR to . for msvc/icl builds, we never need to use
absolute unix style paths for the file output, and we can use the
actual proper form of the file output parameters. This avoids requiring
the c99wrap wrapper for remapping the parameters for cases where the
c99 converter isn't invoked at all (MSVC2013 and ICL).
Signed-off-by: Martin Storsjö <martin@martin.st>

It was mis-spelled in b18c7c8d.
Signed-off-by: Anton Khirnov <anton@khirnov.net>

ICL doesn't return an error on unknown parameters, and will
always pass the symver_gnu_asm test, and since Windows
never has symbol versioning, just always disable it.
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

Signed-off-by: Diego Biurrun <diego@biurrun.de>

The code does in no way depend on CONFIG_SMALL.

On some platforms (such as msys), symlinks are (poorly) emulated
by simply creating a copy of the file.

This means that when building out of tree, the build tree gets
a copy of the original makefile, which can lead to unintuitive
build errors when the original makefile gets updated later.

Instead simply create a stub makefile which includes the real
one.
Signed-off-by: Martin Storsjö <martin@martin.st>

Signed-off-by: Diego Biurrun <diego@biurrun.de>

Signed-off-by: Diego Biurrun <diego@biurrun.de>

data[0] may be NULL for valid frames with hwaccel pixel formats.

This makes RTMPT work again - it was broken by 5d876be8.
Signed-off-by: Martin Storsjö <martin@martin.st>