util: Introduce HAVE_BUILD_ID for build id utils

Build utilities to retrieve the build id are now exposed
through the new HAVE_BUILD_ID instead of HAVE_DL_ITERATE_PHDR
since this will allow adding support for platforms that do
not support HAVE_DL_ITERATE_PHDR

Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/38420>

src/gallium/drivers/virgl/virgl_screen.c

@@ -904,7 +904,7 @@ static void virgl_disk_cache_create(struct virgl_screen *screen)
    struct mesa_sha1 sha1_ctx;
    _mesa_sha1_init(&sha1_ctx);
 
-#ifdef HAVE_DL_ITERATE_PHDR
+#ifdef HAVE_BUILD_ID
    const struct build_id_note *note =
       build_id_find_nhdr_for_addr(virgl_disk_cache_create);
    assert(note);

src/gallium/drivers/zink/zink_screen.c

@@ -303,7 +303,7 @@ disk_cache_init(struct zink_screen *screen)
    struct mesa_blake3 ctx;
    _mesa_blake3_init(&ctx);
 
-#ifdef HAVE_DL_ITERATE_PHDR
+#ifdef HAVE_BUILD_ID
    /* Hash in the zink driver build. */
    const struct build_id_note *note =
        build_id_find_nhdr_for_addr(disk_cache_init);

src/util/build_id.c

@@ -21,13 +21,14 @@
  * IN THE SOFTWARE.
  */
 
-#ifdef HAVE_DL_ITERATE_PHDR
+#include "build_id.h"
+
+#if HAVE_BUILD_ID
 #include <dlfcn.h>
 #include <link.h>
 #include <stddef.h>
 #include <string.h>
 
-#include "build_id.h"
 #include "macros.h"
 
 #ifndef NT_GNU_BUILD_ID

src/util/build_id.h

@@ -24,11 +24,17 @@
 #ifndef BUILD_ID_H
 #define BUILD_ID_H
 
+#if defined(HAVE_DL_ITERATE_PHDR)
+#define HAVE_BUILD_ID 1
+#else
+#define HAVE_BUILD_ID 0
+#endif /* defined(HAVE_DL_ITERATE_PHDR) */
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-#ifdef HAVE_DL_ITERATE_PHDR
+#if HAVE_BUILD_ID
 
 #include <stdint.h>
 

src/util/disk_cache.h

@@ -108,7 +108,7 @@ disk_cache_get_function_identifier(void *ptr, struct mesa_sha1 *ctx)
 {
    uint32_t timestamp;
 
-#ifdef HAVE_DL_ITERATE_PHDR
+#ifdef HAVE_BUILD_ID
    const struct build_id_note *note = NULL;
    if ((note = build_id_find_nhdr_for_addr(ptr))) {
       _mesa_sha1_update(ctx, build_id_data(note), build_id_length(note));