i965: Add INTEL_DEBUG=nocompact to disable instruction compaction.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/mesa/drivers/dri/i965/brw_eu_compact.c

@@ -1407,6 +1407,9 @@ void
 brw_compact_instructions(struct brw_codegen *p, int start_offset,
                          int num_annotations, struct annotation *annotation)
 {
+   if (unlikely(INTEL_DEBUG & DEBUG_NO_COMPACTION))
+      return;
+
    const struct brw_device_info *devinfo = p->devinfo;
    void *store = p->store + start_offset / 16;
    /* For an instruction at byte offset 16*i before compaction, this is the

src/mesa/drivers/dri/i965/intel_debug.c

@@ -74,6 +74,7 @@ static const struct debug_control debug_control[] = {
    { "spill_vec4",  DEBUG_SPILL_VEC4 },
    { "cs",          DEBUG_CS },
    { "hex",         DEBUG_HEX },
+   { "nocompact",   DEBUG_NO_COMPACTION },
    { NULL,    0 }
 };
 

src/mesa/drivers/dri/i965/intel_debug.h

@@ -68,6 +68,7 @@ extern uint64_t INTEL_DEBUG;
 #define DEBUG_SPILL_VEC4          (1ull << 32)
 #define DEBUG_CS                  (1ull << 33)
 #define DEBUG_HEX                 (1ull << 34)
+#define DEBUG_NO_COMPACTION       (1ull << 35)
 
 #ifdef HAVE_ANDROID_PLATFORM
 #define LOG_TAG "INTEL-MESA"