include: drop obsolete check for typeof operator

It really seems that compilers on all our supported platforms
(including Solaris) supporting `typeof`, so we can always use it
and drop hacks with undefind behaviour entirely.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1432>

exa/exa_priv.h

@@ -236,19 +236,11 @@ extern DevPrivateKeyRec exaScreenPrivateKeyRec;
     real->mem = priv->Saved##mem; \
 }
 
-#ifdef HAVE_TYPEOF
 #define swap(priv, real, mem) {\
     typeof(real->mem) tmp = priv->Saved##mem; \
     priv->Saved##mem = real->mem; \
     real->mem = tmp; \
 }
-#else
-#define swap(priv, real, mem) {\
-    const void *tmp = priv->Saved##mem; \
-    priv->Saved##mem = real->mem; \
-    real->mem = tmp; \
-}
-#endif
 
 #define EXA_PRE_FALLBACK(_screen_) \
     ExaScreenPriv(_screen_); \

include/list.h

@@ -274,19 +274,8 @@ xorg_list_is_empty(struct xorg_list *head)
 #define xorg_list_last_entry(ptr, type, member) \
     xorg_list_entry((ptr)->prev, type, member)
 
-#ifdef HAVE_TYPEOF
 #define __container_of(ptr, sample, member)			\
     container_of(ptr, typeof(*sample), member)
-#else
-/* This implementation of __container_of has undefined behavior according
- * to the C standard, but it works in many cases.  If your compiler doesn't
- * support typeof() and fails with this implementation, please try a newer
- * compiler.
- */
-#define __container_of(ptr, sample, member)                            \
-    (void *)((char *)(ptr)                                             \
-            - ((char *)&(sample)->member - (char *)(sample)))
-#endif
 
 /**
  * Loop through the list given by head and set pos to struct in the list.

include/meson.build

@@ -11,11 +11,6 @@ dri_dep = dependency('dri', required: build_glx)
 conf_data = configuration_data()
 conf_data.set('_DIX_CONFIG_H_', '1')
 
-conf_data.set('HAVE_TYPEOF', cc.compiles('''
-    int foo(int bar) { typeof(bar) baz = 1; return baz; }
-''',
-    name: 'typeof()') ? '1' : false)
-
 # For feature macros we're using either false (boolean) or '1', which correspond to the macro being
 # not defined at all and defined to 1. This is to match autotools behavior and thus preserve
 # backwards  compatibility with all the existing code that uses #ifdef to check if feature is