aarch64: fix asm visibility for extern symbols

Commit r271869 broke visibility declarations in asm for extern symbols, because
the new ASM_OUTPUT_EXTERNAL hook failed to call the default hook for elf.

gcc/ChangeLog:

	* config/aarch64/aarch64-protos.h (aarch64_asm_output_external): Remove
	const.
	* config/aarch64/aarch64.c (aarch64_asm_output_external): Call
	default_elf_asm_output_external.

From-SVN: r271913

gcc/ChangeLog

+2019-06-04  Szabolcs Nagy  <szabolcs.nagy@arm.com>
+
+	* config/aarch64/aarch64-protos.h (aarch64_asm_output_external): Remove
+	const.
+	* config/aarch64/aarch64.c (aarch64_asm_output_external): Call
+	default_elf_asm_output_external.
+
 2019-06-04  Martin Liska  <mliska@suse.cz>
 
 	* ipa-icf.c (INCLUDE_LIST): Remove.

gcc/config/aarch64/aarch64-protos.h

@@ -437,7 +437,7 @@ bool aarch64_is_noplt_call_p (rtx);
 bool aarch64_label_mentioned_p (rtx);
 void aarch64_declare_function_name (FILE *, const char*, tree);
 void aarch64_asm_output_alias (FILE *, const tree, const tree);
-void aarch64_asm_output_external (FILE *, const tree, const char*);
+void aarch64_asm_output_external (FILE *, tree, const char*);
 bool aarch64_legitimate_pic_operand_p (rtx);
 bool aarch64_mask_and_shift_for_ubfiz_p (scalar_int_mode, rtx, rtx);
 bool aarch64_masks_and_shift_for_bfi_p (scalar_int_mode, unsigned HOST_WIDE_INT,

gcc/config/aarch64/aarch64.c

@@ -15650,8 +15650,9 @@ aarch64_asm_output_alias (FILE *stream, const tree decl, const tree target)
    function symbol references.  */
 
 void
-aarch64_asm_output_external (FILE *stream, const tree decl, const char* name)
+aarch64_asm_output_external (FILE *stream, tree decl, const char* name)
 {
+  default_elf_asm_output_external (stream, decl, name);
   aarch64_asm_output_variant_pcs (stream, decl, name);
 }