i915: fix nir_to_tgsi() related memory leak

For instance, this issue is triggered with "piglit/bin/glx-multithread-texture -auto -fbo":
Direct leak of 256 byte(s) in 1 object(s) allocated from:
    #0 0xb71eda62 in __interceptor_realloc (/usr/lib/libasan.so.6+0xb2a62)
    #1 0xadd5a32f in tokens_expand ../src/gallium/auxiliary/tgsi/tgsi_ureg.c:239
    #2 0xadd5a32f in get_tokens ../src/gallium/auxiliary/tgsi/tgsi_ureg.c:262
    #3 0xadd62519 in copy_instructions ../src/gallium/auxiliary/tgsi/tgsi_ureg.c:2079
    #4 0xadd62519 in ureg_finalize ../src/gallium/auxiliary/tgsi/tgsi_ureg.c:2129
    #5 0xadd64bde in ureg_get_tokens ../src/gallium/auxiliary/tgsi/tgsi_ureg.c:2206
    #6 0xade377d0 in nir_to_tgsi_options ../src/gallium/auxiliary/nir/nir_to_tgsi.c:4043
    #7 0xade3da63 in nir_to_tgsi ../src/gallium/auxiliary/nir/nir_to_tgsi.c:3831
    #8 0xaeb606c9 in i915_create_vs_state ../src/gallium/drivers/i915/i915_state.c:662
    #9 0xac781a2c in st_create_common_variant ../src/mesa/state_tracker/st_program.c:720
    #10 0xac78e8a4 in st_get_common_variant ../src/mesa/state_tracker/st_program.c:773
    #11 0xac78fc10 in st_precompile_shader_variant ../src/mesa/state_tracker/st_program.c:1259
    #12 0xac78fc10 in st_finalize_program ../src/mesa/state_tracker/st_program.c:1345
    #13 0xac790b1a in st_program_string_notify ../src/mesa/state_tracker/st_program.c:1378
    #14 0xace457a9 in _mesa_get_fixed_func_vertex_program ../src/mesa/main/ffvertex_prog.c:1397
    #15 0xac5ef8db in update_program ../src/mesa/main/state.c:281
    #16 0xac5f0ece in _mesa_update_state_locked ../src/mesa/main/state.c:560
    #17 0xac5f1653 in _mesa_update_state ../src/mesa/main/state.c:593
    #18 0xacdf9fe2 in _mesa_DrawArrays ../src/mesa/main/draw.c:1403

Fixes: 487a493 ("i915g: Add support for per-vertex point size.")
Signed-off-by: Patrick Lerda <[email protected]>
Reviewed-by: Emma Anholt <[email protected]>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27570>

Author: Patrick Lerda

src/gallium/drivers/i915/i915_state.c

@@ -658,6 +658,7 @@ i915_create_vs_state(struct pipe_context *pipe,
                      const struct pipe_shader_state *templ)
 {
    struct i915_context *i915 = i915_context(pipe);
+   void *vertex_shader;
 
    struct pipe_shader_state from_nir = {PIPE_SHADER_IR_TGSI};
    if (templ->type == PIPE_SHADER_IR_NIR) {
@@ -674,7 +675,11 @@ i915_create_vs_state(struct pipe_context *pipe,
       templ = &from_nir;
    }
 
-   return draw_create_vertex_shader(i915->draw, templ);
+   vertex_shader = draw_create_vertex_shader(i915->draw, templ);
+
+   FREE((void *)from_nir.tokens);
+
+   return vertex_shader;
 }
 
 static void