tests/fp/fp-test: add floating point tests

By leveraging berkeley's softfloat and testfloat.

With this we get decent coverage of softfloat.c:

$ ./fp-test -r even:	67.22% coverage
$ ./fp-test -r all:	73.11% coverage

Note that we do not yet test parts of softfloat.c that aren't
in the original softfloat library, namely:

- denormal inputs
- *_to_int16/uint16 conversions
- scalbn for fixed point
- muladd variants
- min/max
- exp2
- log2
- float*_compare (except float16_compare)

Signed-off-by: Emilio G. Cota <cota@braap.org>
[rth: Add the new modules to git_submodules.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

configure

@@ -296,6 +296,8 @@ if test -e "$source_path/.git"
 then
     git_update=yes
     git_submodules="ui/keycodemapdb"
+    git_submodules="$git_submodules tests/fp/berkeley-testfloat-3"
+    git_submodules="$git_submodules tests/fp/berkeley-softfloat-3"
 else
     git_update=no
     git_submodules=""
@@ -7449,12 +7451,14 @@ fi
 
 # build tree in object directory in case the source is not in the current directory
 DIRS="tests tests/tcg tests/tcg/cris tests/tcg/lm32 tests/libqos tests/qapi-schema tests/tcg/xtensa tests/qemu-iotests tests/vm"
+DIRS="$DIRS tests/fp"
 DIRS="$DIRS docs docs/interop fsdev scsi"
 DIRS="$DIRS pc-bios/optionrom pc-bios/spapr-rtas pc-bios/s390-ccw"
 DIRS="$DIRS roms/seabios roms/vgabios"
 FILES="Makefile tests/tcg/Makefile qdict-test-data.txt"
 FILES="$FILES tests/tcg/cris/Makefile tests/tcg/cris/.gdbinit"
 FILES="$FILES tests/tcg/lm32/Makefile tests/tcg/xtensa/Makefile po/Makefile"
+FILES="$FILES tests/fp/Makefile"
 FILES="$FILES pc-bios/optionrom/Makefile pc-bios/keymaps"
 FILES="$FILES pc-bios/spapr-rtas/Makefile"
 FILES="$FILES pc-bios/s390-ccw/Makefile"