gallium/dri: Add shared glapi to LIBADD on Android

An earlier patch fixed the problem for classic drivers, however Gallium
was still left broken. This patch applies the same workaround to
Gallium, when compiled for Android. Following is a quote from the
original patch:

0cbc90c57c mesa: dri: Add shared glapi to LIBADD on Android

/system/vendor/lib/dri/*_dri.so actually depend on libglapi: without
this, loading the so file fails with:
cannot locate symbol "__emutls_v._glapi_tls_Context"

On non-Android (non-bionic) platform, EGL uses the following
workflow, which works fine:
  dlopen("libglapi.so", RTLD_LAZY | RTLD_GLOBAL);
  dlopen("dri/<driver>_dri.so", RTLD_NOW | RTLD_GLOBAL);

However, bionic does not respect the RTLD_GLOBAL flag, and the dri
library cannot find symbols in libglapi.so, so we need to link
to libglapi.so explicitly. Android.mk already does this.

Cc: "12.0" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>

src/gallium/targets/dri/Makefile.am

@@ -1,5 +1,11 @@
 include $(top_srcdir)/src/gallium/Automake.inc
 
+if HAVE_ANDROID
+if HAVE_SHARED_GLAPI
+SHARED_GLAPI_LIB = $(top_builddir)/src/mapi/shared-glapi/libglapi.la
+endif
+endif
+
 AM_CFLAGS = \
 	-I$(top_srcdir)/src/mapi \
 	-I$(top_srcdir)/src/mesa \
@@ -49,6 +55,7 @@ gallium_dri_la_LIBADD = \
 	$(top_builddir)/src/gallium/drivers/noop/libnoop.la \
 	$(top_builddir)/src/gallium/drivers/rbug/librbug.la \
 	$(top_builddir)/src/gallium/drivers/trace/libtrace.la \
+	$(SHARED_GLAPI_LIB) \
 	$(SELINUX_LIBS) \
 	$(EXPAT_LIBS) \
 	$(LIBDRM_LIBS) \