gh-136229: Remove Platform Emscripten is not supported warning (#136230)

Updates configure script to identify Emscripten as Tier 3.

Author: hoodmane

configure

@@ -1208,27 +1208,28 @@ dnl NOTE: Windows support tiers are defined in PC/pyconfig.h.
 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
-  [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
-  [wasm32-unknown-wasip1/clang],     [PY_SUPPORT_TIER=2], dnl WebAssembly System Interface preview1, clang
-  [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/clang],   [PY_SUPPORT_TIER=3], dnl Linux on PPC64 little endian, glibc, clang
-  [s390x-*-linux-gnu/gcc],           [PY_SUPPORT_TIER=3], dnl Linux on 64bit s390x (big endian), glibc, gcc
-  [x86_64-*-freebsd*/clang],         [PY_SUPPORT_TIER=3], dnl FreeBSD on AMD64
-  [aarch64-apple-ios*-simulator/clang],   [PY_SUPPORT_TIER=3], dnl iOS Simulator on arm64
-  [aarch64-apple-ios*/clang],             [PY_SUPPORT_TIER=3], dnl iOS on ARM64
-  [aarch64-*-linux-android/clang],   [PY_SUPPORT_TIER=3], dnl Android on ARM64
-  [x86_64-*-linux-android/clang],    [PY_SUPPORT_TIER=3], dnl Android on AMD64
+  [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
+  [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
+  [wasm32-unknown-wasip1/clang],         [PY_SUPPORT_TIER=2], dnl WebAssembly System Interface preview1, clang
+  [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/clang],       [PY_SUPPORT_TIER=3], dnl Linux on PPC64 little endian, glibc, clang
+  [s390x-*-linux-gnu/gcc],               [PY_SUPPORT_TIER=3], dnl Linux on 64bit s390x (big endian), glibc, gcc
+  [x86_64-*-freebsd*/clang],             [PY_SUPPORT_TIER=3], dnl FreeBSD on AMD64
+  [aarch64-apple-ios*-simulator/clang],  [PY_SUPPORT_TIER=3], dnl iOS Simulator on arm64
+  [aarch64-apple-ios*/clang],            [PY_SUPPORT_TIER=3], dnl iOS on ARM64
+  [aarch64-*-linux-android/clang],       [PY_SUPPORT_TIER=3], dnl Android on ARM64
+  [x86_64-*-linux-android/clang],        [PY_SUPPORT_TIER=3], dnl Android on AMD64
+  [wasm32-*-emscripten/emcc],            [PY_SUPPORT_TIER=3], dnl Emscripten
 
   [PY_SUPPORT_TIER=0]
 )