i965/vs: Move struct brw_compile (p) entirely inside vec4_generator.

The brw_compile structure contains the brw_instruction store and the
brw_eu_emit.c state tracking fields.  These are only useful for the
final assembly generation pass; the earlier compilation stages doesn't
need them.

This also means that the code generator for future hardware won't have
access to the brw_compile structure, which is extremely desirable
because it prevents accidental generation of Gen4-7 code.

Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Anuj Phogat <anuj.phogat@gmail.com>

src/mesa/drivers/dri/i965/brw_vec4.cpp

@@ -1136,8 +1136,6 @@ brw_vs_emit(struct brw_context *brw,
    bool start_busy = false;
    float start_time = 0;
 
-   brw_init_compile(brw, &c->func, mem_ctx);
-
    if (unlikely(INTEL_DEBUG & DEBUG_PERF)) {
       start_busy = (intel->batch.last_bo &&
                     drm_intel_bo_busy(intel->batch.last_bo));

src/mesa/drivers/dri/i965/brw_vec4_emit.cpp

@@ -140,7 +140,9 @@ vec4_generator::vec4_generator(struct brw_context *brw,
 {
    intel = &brw->intel;
    vp = &c->vp->program;
-   p = &c->func;
+
+   p = rzalloc(mem_ctx, struct brw_compile);
+   brw_init_compile(brw, p, mem_ctx);
 }
 
 vec4_generator::~vec4_generator()

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

@@ -94,7 +94,6 @@ struct brw_vs_prog_key {
 
 
 struct brw_vs_compile {
-   struct brw_compile func;
    struct brw_vs_prog_key key;
    struct brw_vs_prog_data prog_data;