xen: Drop CONFIG_CC_HAS_VISIBILITY_ATTRIBUTE

All supported toolchains now have it.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>

xen/Kconfig

@@ -29,10 +29,6 @@ config LD_IS_GNU
 config LD_IS_LLVM
 	def_bool $(success,$(LD) --version | head -n 1 | grep -q "^LLD")
 
-# -fvisibility=hidden reduces -fpic cost, if it's available
-config CC_HAS_VISIBILITY_ATTRIBUTE
-	def_bool $(cc-option,-fvisibility=hidden)
-
 # Use -f{function,data}-sections compiler parameters
 config CC_SPLIT_SECTIONS
 	bool

xen/include/xen/compiler.h

@@ -17,10 +17,8 @@
 
 #endif /* Compiler checks. */
 
-#ifdef CONFIG_CC_HAS_VISIBILITY_ATTRIBUTE
 /* Results in more efficient PIC code (no indirections through GOT or PLT). */
 #pragma GCC visibility push(hidden)
-#endif
 
 #define barrier()     __asm__ __volatile__("": : :"memory")