[Bug target/113341] Using GCC as the bootstrap compiler breaks LLVM on 32-bit PowerPC

["glaubitz at physik dot fu-berlin.de" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113341

--- Comment #11 from John Paul Adrian Glaubitz <glaubitz at physik dot fu-berlin.de> ---
(In reply to John Paul Adrian Glaubitz from comment #10)
> (In reply to Kewen Lin from comment #9)
> > Since it's a breakage during stage2, it's concluded that some built stage1
> > stuffs behave unexpectedly.  You probably can try to run regression testing
> > just with stage1 compiler to see if there is any regression exposed.
> > 
> > If without any luck, then you probably have to isolate into one or several
> > object files, since you have "objects" for "good" and "bad" stage1 compiler,
> > you can be able to isolate some in between further. Once you get some
> > isolated, you can probably get some hints it's a bug in LLVM source or gcc.
> 
> Thanks. This sounds like a good idea. I will try to identify the object
> files that differ.

First result of the comparison is that Clang and GCC are building with
different flags:

Clang-only flags: -Werror=unguarded-availability-new -Wc++98-compat-extra-semi
-Wcovered-switch-default -Wnon-virtual-dtor -Wstring-conversion
-Wmisleading-indentation

GCC-only flags:  -fno-lifetime-dse    -Wno-missing-field-initializers  
-Wno-maybe-uninitialized -Wno-nonnull -Wno-class-memaccess -Wno-redundant-move
-Wno-pessimizing-move    -Wno-comment -Wno-misleading-indentation

I'll upload the build results later to my cloud space if anyone wants to help
debug as the diff between the two build folders is rather big.