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docs: Delete incorrect code generation section of HowToSubmitABug (#182315)

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I've never used this. Based on the description here, I'm assuming
it relied on the C backend, which was removed in 2012.
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llvm/docs/HowToSubmitABug.rst
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@ -247,71 +247,3 @@ resulting error.
The :doc:`OptBisect <OptBisect>` page shows an alternative method for finding
incorrect optimization passes.
Incorrect code generation
=========================
Similarly to debugging incorrect compilation by mis-behaving passes, you
can debug incorrect code generation by either LLC or the JIT, using
``bugpoint``. The process ``bugpoint`` follows in this case is to try to
narrow the code down to a function that is miscompiled by one or the other
method, but since for correctness, the entire program must be run,
``bugpoint`` will compile the code it deems to not be affected with the C
Backend, and then link in the shared object it generates.
To debug the JIT:
.. code-block:: bash
bugpoint -run-jit -output=[correct output file] [bitcode file] \
--tool-args -- [arguments to pass to lli] \
--args -- [program arguments]
Similarly, to debug the LLC, one would run:
.. code-block:: bash
bugpoint -run-llc -output=[correct output file] [bitcode file] \
--tool-args -- [arguments to pass to llc] \
--args -- [program arguments]
**Special note:** if you are debugging MultiSource or SPEC tests that
already exist in the ``llvm/test`` hierarchy, there is an easier way to
debug the JIT, LLC, and CBE, using the pre-written Makefile targets, which
will pass the program options specified in the Makefiles:
.. code-block:: bash
cd llvm/test/../../program
make bugpoint-jit
At the end of a successful ``bugpoint`` run, you will be presented
with two bitcode files: a *safe* file which can be compiled with the C
backend and the *test* file which either LLC or the JIT
mis-codegenerates, and thus causes the error.
To reproduce the error that ``bugpoint`` found, it is sufficient to do
the following:
#. Regenerate the shared object from the safe bitcode file:
.. code-block:: bash
llc -march=c safe.bc -o safe.c
gcc -shared safe.c -o safe.so
#. If debugging LLC, compile test bitcode native and link with the shared
object:
.. code-block:: bash
llc test.bc -o test.s
gcc test.s safe.so -o test.llc
./test.llc [program options]
#. If debugging the JIT, load the shared object and supply the test
bitcode:
.. code-block:: bash
lli -load=safe.so test.bc [program options]