go: update usage of TARGET_AIX to TARGET_AIX_OS

TARGET_AIX is defined to a non-zero value on linux and maybe other
powerpc64le targets.  This leads to unexpected behavior such as
dropping the .go_export section when linking a shared library
on linux/powerpc64le.

Instead, use TARGET_AIX_OS to toggle AIX specific behavior.

Fixes golang/go#60798.

gcc/go/ChangeLog:

	* go-backend.cc [TARGET_AIX]: Rename and update usage to
	TARGET_AIX_OS.
	* go-lang.cc: Likewise.

Author: Paul E. Murphy

gcc/go/go-backend.cc

@@ -45,8 +45,8 @@ along with GCC; see the file COPYING3.  If not see
 #define GO_EXPORT_SECTION_NAME ".go_export"
 #endif
 
-#ifndef TARGET_AIX
-#define TARGET_AIX 0
+#ifndef TARGET_AIX_OS
+#define TARGET_AIX_OS 0
 #endif
 
 /* This file holds all the cases where the Go frontend needs
@@ -107,7 +107,7 @@ go_write_export_data (const char *bytes, unsigned int size)
     {
       gcc_assert (targetm_common.have_named_sections);
       sec = get_section (GO_EXPORT_SECTION_NAME,
-			 TARGET_AIX ? SECTION_EXCLUDE : SECTION_DEBUG,
+			 TARGET_AIX_OS ? SECTION_EXCLUDE : SECTION_DEBUG,
 			 NULL);
     }
 

gcc/go/go-lang.cc

@@ -39,8 +39,8 @@ along with GCC; see the file COPYING3.  If not see
 #include "go-c.h"
 #include "go-gcc.h"
 
-#ifndef TARGET_AIX
-#define TARGET_AIX 0
+#ifndef TARGET_AIX_OS
+#define TARGET_AIX_OS 0
 #endif
 
 /* Language-dependent contents of a type.  */
@@ -116,9 +116,9 @@ go_langhook_init (void)
   args.compiling_runtime = go_compiling_runtime;
   args.debug_escape_level = go_debug_escape_level;
   args.debug_escape_hash = go_debug_escape_hash;
-  args.nil_check_size_threshold = TARGET_AIX ? -1 : 4096;
+  args.nil_check_size_threshold = TARGET_AIX_OS ? -1 : 4096;
   args.debug_optimization = go_debug_optimization;
-  args.need_eqtype = TARGET_AIX ? true : false;
+  args.need_eqtype = TARGET_AIX_OS ? true : false;
   args.linemap = go_get_linemap();
   args.backend = go_get_backend();
   go_create_gogo (&args);