[Bug middle-end/106495] [13 Regression] Build fails gcc/tree-ssa-threadbackward.cc:22: gcc/vec.h:890:19: error: array subscript 4294967294 is above array bounds of 'basic_block_def* [1]' [-Werror=array-bounds]

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106495

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
Created attachment 53395
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53395&action=edit
preprocessed source, trimmed at tail

preprocessed source for i686-pc-linux-gnu, reproduce with

./cc1plus -fpreprocessed tree-ssa-threadbackward.ii -quiet -dumpbase
tree-ssa-threadbackward.cc -dumpbase-ext .cc -mtune=generic -march=pentiumpro
-g -gtoggle -O2 -Wextra -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual
-Wsuggest-attribute=format -Woverloaded-virtual=2 -Wpedantic -Wno-long-long
-Wno-variadic-macros -Wno-overlength-strings -Werror -version -fno-PIE
-fno-checking -fno-exceptions -fno-rtti -fasynchronous-unwind-tables
-fno-common -o tree-ssa-threadbackward.s