tree-wide: use __normal_user() everywhere instead of writing the check manually

Cc: mesa-stable
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/27346>

src/gallium/frontends/dri/dri_context.c

@@ -169,7 +169,7 @@ dri_create_context(struct dri_screen *screen,
    if (debug_get_bool_option("MESA_NO_ERROR", false) ||
        driQueryOptionb(&screen->dev->option_cache, "mesa_no_error"))
 #if !defined(_WIN32)
-      if (geteuid() == getuid())
+      if (__normal_user())
 #endif
          attribs.flags |= ST_CONTEXT_FLAG_NO_ERROR;
 

src/intel/compiler/brw_shader.cpp

@@ -29,6 +29,7 @@
 #include "brw_vec4_tes.h"
 #include "dev/intel_debug.h"
 #include "util/macros.h"
+#include "util/u_debug.h"
 
 enum brw_reg_type
 brw_type_for_base_type(const struct glsl_type *type)
@@ -1230,7 +1231,7 @@ void
 backend_shader::dump_instructions(const char *name) const
 {
    FILE *file = stderr;
-   if (name && geteuid() != 0) {
+   if (name && __normal_user()) {
       file = fopen(name, "w");
       if (!file)
          file = stderr;

src/loader/loader.c

@@ -675,7 +675,7 @@ loader_get_driver_for_fd(int fd)
     * user's problem, but this allows vc4 simulator to run on an i965 host,
     * and may be useful for some touch testing of i915 on an i965 host.
     */
-   if (geteuid() == getuid()) {
+   if (__normal_user()) {
       const char *override = os_get_option("MESA_LOADER_DRIVER_OVERRIDE");
       if (override)
          return strdup(override);
@@ -780,7 +780,7 @@ loader_open_driver_lib(const char *driver_name,
    const char *search_paths, *next, *end;
 
    search_paths = NULL;
-   if (geteuid() == getuid() && search_path_vars) {
+   if (__normal_user() && search_path_vars) {
       for (int i = 0; search_path_vars[i] != NULL; i++) {
          search_paths = getenv(search_path_vars[i]);
          if (search_paths)

src/util/disk_cache_os.c

@@ -34,6 +34,7 @@
 
 #include "util/compress.h"
 #include "util/crc32.h"
+#include "util/u_debug.h"
 #include "util/disk_cache.h"
 #include "util/disk_cache_os.h"
 
@@ -980,7 +981,7 @@ disk_cache_enabled()
       return false;
 
    /* If running as a users other than the real user disable cache */
-   if (geteuid() != getuid())
+   if (!__normal_user())
       return false;
 
    /* At user request, disable shader cache entirely. */

src/util/log.c

@@ -94,7 +94,7 @@ mesa_log_init_once(void)
    mesa_log_file = stderr;
 
 #if !DETECT_OS_WINDOWS
-   if (geteuid() == getuid()) {
+   if (__normal_user()) {
       const char *log_file = os_get_option("MESA_LOG_FILE");
       if (log_file) {
          FILE *fp = fopen(log_file, "w");