gallium/tests/trivial: Switch to the pipe loader.

It simplifies things slightly, and besides, it makes possible to
execute the trivial tests on a hardware device instead of being
limited to software rendering.

Reviewed-by: Jakob Bornecrantz <jakob@vmware.com>
diff --git a/configure.ac b/configure.ac
index 4b26e72..3c742cd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -643,6 +643,12 @@
     [enable_r600_llvm="$enableval"],
     [enable_r600_llvm=no])
 
+AC_ARG_ENABLE([gallium_tests],
+    [AS_HELP_STRING([--enable-gallium-tests],
+        [Enable optional Gallium tests) @<:@default=disable@:>@])],
+    [enable_gallium_tests="$enableval"],
+    [enable_gallium_tests=no])
+
 # Option for Gallium drivers
 GALLIUM_DRIVERS_DEFAULT="r300,r600,svga,swrast"
 
@@ -1967,6 +1973,11 @@
     done
 fi
 
+if test "x$enable_gallium_tests" = xyes; then
+    SRC_DIRS="$SRC_DIRS gallium/tests/trivial"
+    enable_gallium_loader=yes
+fi
+
 if test "x$enable_gallium_loader" = xyes; then
     GALLIUM_WINSYS_DIRS="$GALLIUM_WINSYS_DIRS sw/null"
     GALLIUM_PIPE_LOADER_DEFINES="-DHAVE_PIPE_LOADER_SW"