Import CPython 3.14.8+ stable branch (2026-10-07)

Summary:
Imported python/cpython `3.14.8+` from upstream rev [`6490ca6`](https://www.github.com/python/cpython/commit/6490ca6f0335c80c8aa546714dbce466a261a2dd) (committed 2026-10-07 05:35:16+00:00).

# Commit Info

- Base: (`3.14.8+`) - [`fb313a3`](https://www.github.com/python/cpython/commit/fb313a3948fb27e18f68c1df9deaa79c2fd394f2) (commit date: 2026-10-06 16:13:01+00:00)
- Imported: (`3.14.8+`) - [`6490ca6`](https://www.github.com/python/cpython/commit/6490ca6f0335c80c8aa546714dbce466a261a2dd) (commit date: 2026-10-07 05:35:16+00:00)

# Noteworthy file changes

- Low-signal files (1 added) (NEWS.d, docs, .github)

Complete list of added/removed files: https://www.internalfb.com/intern/everpaste/?color=0&handle=GNB1DDGWO4E6vuYDAGopOrHL6VIWbr0LAAAz

Reviewed By: jermenkoo, itamaro

Differential Revision: D124091648

fbshipit-source-id: dfa5518429b44687ab8f670362f2f597ee1a4b15

Author: generatedunixname1734921407115435

Misc/NEWS.d/next/Windows/2026-09-19-13-18-48.gh-issue-157789.o6-rmo.rst

@@ -0,0 +1,2 @@
+Use compiler option ``-Og`` in case of clang-cl debug builds on Windows to
+reduce stack usage. Patch by Chris Eibl.

PCbuild/pyproject-clangcl.props

@@ -50,6 +50,7 @@
       <AdditionalOptions Condition="'$(Platform)' == 'Win32'">-m32 %(AdditionalOptions)</AdditionalOptions>
       <AdditionalOptions Condition="'$(Platform)' == 'x64'">-m64 %(AdditionalOptions)</AdditionalOptions>
       <AdditionalOptions Condition="$(Configuration) != 'Debug'">-flto=thin %(AdditionalOptions)</AdditionalOptions>
+      <AdditionalOptions Condition="$(Configuration) == 'Debug'">%(AdditionalOptions) -Xclang -Og</AdditionalOptions>
       <AdditionalOptions Condition="$(SupportPGO) and $(Configuration) == 'PGInstrument'">-fprofile-instr-generate=$(_CLANG_PROFILE_PATH)$(TargetName)_%m.profraw %(AdditionalOptions)</AdditionalOptions>
       <AdditionalOptions Condition="$(SupportPGO) and $(Configuration) == 'PGUpdate'">-fprofile-instr-use=$(OutDir)instrumented\profdata.profdata -Wno-profile-instr-unprofiled %(AdditionalOptions)</AdditionalOptions>
     </ClCompile>