configure.ac/meson.build: Add options for library suffixes

When building the Chrome OS Android container, we need to build copies
of mesa that don't conflict with the Android system-supplied libraries.
This adds options to create suffixed versions of EGL and GLES libraries:

libEGL.so -> libEGL${egl-lib-suffix}.so
libGLESv1_CM.so -> libGLESv1_CM${gles-lib-suffix}.so
libGLESv2.so -> libGLES${gles-lib-suffix}.so

This is similar to what happens when --enable-libglvnd is specified, but
without the side effects of linking against libglvnd.  To avoid
unexpected clashes with the suffixed appended by libglvnd, make it an
error to specify both --enable-libglvnd and --with-egl-lib-suffix.

Reviewed-by: Eric Engestrom <eric.engestrom@intel.com>
diff --git a/meson.build b/meson.build
index 7a53698..7b33775 100644
--- a/meson.build
+++ b/meson.build
@@ -375,6 +375,9 @@
   elif with_glx == 'disabled' and not with_egl
     error('glvnd requires DRI based GLX and/or EGL')
   endif
+  if get_option('egl-lib-suffix') != ''
+    error('''EGL lib suffix can't be used with libglvnd''')
+  endif
 endif
 
 if with_vulkan_icd_dir == ''