Summary

• Manual backport of gh-156091: Fix crash compiling deeply nested inlined comprehensions #156957 / [3.14] gh-156091: Fix crash compiling deeply nested inlined comprehensions (GH-156957) #156993 to 3.13 (miss-islington conflicted).
• 3.13 still has inlined-comprehension codegen in Python/compile.c with the old fblocktype names, so the fblock is INLINED_COMPREHENSION rather than COMPILE_FBLOCK_INLINED_COMPREHENSION.
• Nested inlined comprehensions with locals now count toward CO_MAXBLOCKS and raise SyntaxError instead of overflowing the except stack.

Test plan

• ./python.exe -m test test_syntax -m test_nested_inlined_comprehensions_block_limit

Made with Cursor

• Issue: Compiler crash: inlined comprehensions overflow _PyCfgExceptStack, bypassing the u_nfblocks block-nesting limit #156091