GH-156554: Update PY_SUPPORT_TIER according to PEP 11 (#156576)

Author: chris-eibl

Misc/NEWS.d/next/Build/2026-08-29-15-14-45.gh-issue-156554.64SZb1.rst

@@ -0,0 +1,3 @@
+Update ``PY_SUPPORT_TIER`` according to :pep:`11` for these target triples:
+``aarch64-*-linux-gnu/gcc``, ``aarch64-pc-windows-msvc/msvc``,
+``x86_64-apple-darwin*/clang``, and ``powerpc64le-*-linux-gnu/gcc``.

PC/pyconfig.h

@@ -152,7 +152,7 @@ WIN32 is still required for the locale module.
  *
  * win_amd64 MSVC (x86_64-pc-windows-msvc): 1
  * win32 MSVC (i686-pc-windows-msvc): 1
- * win_arm64 MSVC (aarch64-pc-windows-msvc): 3
+ * win_arm64 MSVC (aarch64-pc-windows-msvc): 2
  * other archs and ICC: 0
  */
 #ifdef MS_WIN64
@@ -170,7 +170,7 @@ WIN32 is still required for the locale module.
 #define PYD_PLATFORM_TAG "win_amd64"
 #elif defined(_M_ARM64)
 #define _Py_COMPILER _Py_PASTE_VERSION("64 bit (ARM64)")
-#define PY_SUPPORT_TIER 3
+#define PY_SUPPORT_TIER 2
 #define PYD_PLATFORM_TAG "win_arm64"
 #else
 #define _Py_COMPILER _Py_PASTE_VERSION("64 bit (Unknown)")

configure

@@ -1247,19 +1247,19 @@ dnl
 AC_MSG_CHECKING([for PEP 11 support tier])
 AS_CASE([$host/$ac_cv_cc_name],
   [x86_64-*-linux-gnu/gcc],              [PY_SUPPORT_TIER=1], dnl Linux on AMD64, any vendor, glibc, gcc
-  [x86_64-apple-darwin*/clang],          [PY_SUPPORT_TIER=1], dnl macOS on Intel, any version
   [aarch64-apple-darwin*/clang],         [PY_SUPPORT_TIER=1], dnl macOS on M1, any version
+  [aarch64-*-linux-gnu/gcc],             [PY_SUPPORT_TIER=1], dnl Linux ARM64, glibc, gcc
   [i686-pc-windows-msvc/msvc],           [PY_SUPPORT_TIER=1], dnl 32bit Windows on Intel, MSVC
   [x86_64-pc-windows-msvc/msvc],         [PY_SUPPORT_TIER=1], dnl 64bit Windows on AMD64, MSVC
 
-  [aarch64-*-linux-gnu/gcc],             [PY_SUPPORT_TIER=2], dnl Linux ARM64, glibc, gcc+clang
-  [aarch64-*-linux-gnu/clang],           [PY_SUPPORT_TIER=2],
-  [powerpc64le-*-linux-gnu/gcc],         [PY_SUPPORT_TIER=2], dnl Linux on PPC64 little endian, glibc, gcc
+  [aarch64-*-linux-gnu/clang],           [PY_SUPPORT_TIER=2], dnl Linux ARM64, glibc, clang
+  [aarch64-pc-windows-msvc/msvc],        [PY_SUPPORT_TIER=2], dnl Windows ARM64, MSVC
   [wasm32-unknown-wasip1/clang],         [PY_SUPPORT_TIER=2], dnl WebAssembly System Interface preview1, clang
+  [x86_64-apple-darwin*/clang],          [PY_SUPPORT_TIER=2], dnl macOS on Intel, any version
   [x86_64-*-linux-gnu/clang],            [PY_SUPPORT_TIER=2], dnl Linux on AMD64, any vendor, glibc, clang
 
-  [aarch64-pc-windows-msvc/msvc],        [PY_SUPPORT_TIER=3], dnl Windows ARM64, MSVC
   [armv7l-*-linux-gnueabihf/gcc],        [PY_SUPPORT_TIER=3], dnl ARMv7 LE with hardware floats, any vendor, glibc, gcc
+  [powerpc64le-*-linux-gnu/gcc],         [PY_SUPPORT_TIER=3], dnl Linux on PPC64 little endian, glibc, gcc
   [powerpc64le-*-linux-gnu/clang],       [PY_SUPPORT_TIER=3], dnl Linux on PPC64 little endian, glibc, clang
   [riscv64-*-linux-gnu/gcc],             [PY_SUPPORT_TIER=3], dnl Linux on RISC-V 64bit, glibc, gcc+clang
   [riscv64-*-linux-gnu/clang],           [PY_SUPPORT_TIER=3],