ir_to_mesa: Let check_resources halt compilation

ir_to_mesa: Let check_resources halt compilation

Previously check_resources could fail, but we'd still try to optimize
the shader, do device-specific code generation, etc.  In some cases,
this could explode (especially in the device-specific code
generation).  I haven't found that I could trigger this with the
current code.  When too many samplers were used with the new uniform
handling code, I observed several crashes deep down in the driver.

NOTE: This is candidate for the 7.11 branch.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=41609
Cc: Eric Anholt <eric@anholt.net>
Reviewed-and-tested-by: Kenneth Graunke <kenneth@whitecape.org>