clarified platforms;

--- a/src/Pure/Admin/build_polyml.scala	Tue May 11 12:21:39 2021 +0200
+++ b/src/Pure/Admin/build_polyml.scala	Tue May 11 13:06:36 2021 +0200
@@ -48,12 +48,9 @@
       error("Bad Poly/ML root directory: " + root)
 
     val platform = Isabelle_Platform.self
-    val platform_arch =
-      if (arch_64) platform.arch_64
-      else if (platform.is_intel) "x86_64_32"
-      else platform.arch_32
 
-    val polyml_platform = platform_arch + "-" + platform.os_name
+    val polyml_platform =
+      (if (arch_64) platform.arch_64 else platform.arch_64_32) + "-" + platform.os_name
     val sha1_platform = platform.arch_64 + "-" + platform.os_name
 
     val info =
@@ -204,7 +201,7 @@
     Isabelle_Tool("build_polyml", "build Poly/ML from sources", Scala_Project.here, args =>
     {
       var mingw = MinGW.none
-      var arch_64 = Isabelle_Platform.self.is_arm
+      var arch_64 = false
       var sha1_root: Option[Path] = None
 
       val getopts = Getopts("""

--- a/src/Pure/System/isabelle_platform.scala	Tue May 11 12:21:39 2021 +0200
+++ b/src/Pure/System/isabelle_platform.scala	Tue May 11 13:06:36 2021 +0200
@@ -15,7 +15,8 @@
       "ISABELLE_PLATFORM32",
       "ISABELLE_PLATFORM64",
       "ISABELLE_WINDOWS_PLATFORM32",
-      "ISABELLE_WINDOWS_PLATFORM64")
+      "ISABELLE_WINDOWS_PLATFORM64",
+      "ISABELLE_APPLE_PLATFORM64")
 
   def apply(ssh: Option[SSH.Session] = None): Isabelle_Platform =
   {
@@ -46,25 +47,21 @@
       getOrElse(error("Bad platform settings variable: " + quote(name)))
 
   val ISABELLE_PLATFORM_FAMILY: String = get("ISABELLE_PLATFORM_FAMILY")
-  val ISABELLE_PLATFORM32: String = get("ISABELLE_PLATFORM32")
   val ISABELLE_PLATFORM64: String = get("ISABELLE_PLATFORM64")
-  val ISABELLE_WINDOWS_PLATFORM32: String = get("ISABELLE_WINDOWS_PLATFORM32")
   val ISABELLE_WINDOWS_PLATFORM64: String = get("ISABELLE_WINDOWS_PLATFORM64")
-
-  def is_intel: Boolean =
-    ISABELLE_PLATFORM32.startsWith("x86-") ||
-    ISABELLE_PLATFORM64.startsWith("x86_64-")
+  val ISABELLE_APPLE_PLATFORM64: String = get("ISABELLE_APPLE_PLATFORM64")
 
   def is_arm: Boolean =
-    ISABELLE_PLATFORM32.startsWith("arm32-") ||
-    ISABELLE_PLATFORM64.startsWith("arm64-")
+    ISABELLE_PLATFORM64.startsWith("arm64-") ||
+    ISABELLE_APPLE_PLATFORM64.startsWith("arm64-")
 
   def is_linux: Boolean = ISABELLE_PLATFORM_FAMILY == "linux"
   def is_macos: Boolean = ISABELLE_PLATFORM_FAMILY == "macos"
   def is_windows: Boolean = ISABELLE_PLATFORM_FAMILY == "windows"
 
-  def arch_32: String = if (is_arm) "arm32" else "x86"
   def arch_64: String = if (is_arm) "arm64" else "x86_64"
+  def arch_64_32: String = if (is_arm) "arm64_32" else "x86_64_32"
+
   def os_name: String = if (is_macos) "darwin" else ISABELLE_PLATFORM_FAMILY
 
   override def toString: String = ISABELLE_PLATFORM_FAMILY