Nanomips qemu runner

[nikolaperic]

Fixed issues when running tests from llvm-test-sute.

Qemu runner script has been added.

Cmake config:

TOOLCHAIN_DIR="/home/syrmia/llvm-nanomips/nanomips-elf/2022.03-01"
TEST_SUITE_DIR="/home/syrmia/llvm-nanomips/llvm-test-suite"
cmake -G Ninja \
	-DCMAKE_C_COMPILER=$TOOLCHAIN_DIR/bin/clang \
	-C$TEST_SUITE_DIR/cmake/caches/Os.cmake \
	-DTEST_SUITE_RUN_UNDER="$TEST_SUITE_DIR/run-under-qemu.sh $TOOLCHAIN_DIR/bin/qemu-system-nanomips I7200" \
	-DCMAKE_C_FLAGS="--target=nanomips-elf -march=i7200 -mcpu=i7200 -I $TOOLCHAIN_DIR/nanomips-elf/include -I $TOOLCHAIN_DIR/lib/gcc/nanomips-elf/11.2.0/include-fixed -T$TOOLCHAIN_DIR/nanomips-elf/lib/nanomips-r6-soft-tiny/lib/uhi32.ld -Wl,--defsym,__memory_size=256M" \
	-DCMAKE_CXX_COMPILER=$TOOLCHAIN_DIR/bin/clang++ \
	-DCMAKE_CXX_FLAGS="--target=nanomips-elf -march=i7200 -mcpu=i7200 -I $TOOLCHAIN_DIR/nanomips-elf/include -I $TOOLCHAIN_DIR/lib/gcc/nanomips-elf/11.2.0/include-fixed -T$TOOLCHAIN_DIR/nanomips-elf/lib/nanomips-r6-soft-tiny/lib/uhi32.ld -Wl,--defsym,__memory_size=256M" \
	-DTEST_SUITE_COLLECT_CODE_SIZE=OFF \
	-DTEST_SUITE_USE_PERF=ON \
	-DTEST_SUITE_HOST_CC=gcc \
	-DTEST_SUITE_USER_MODE_EMULATION=ON \
	-DTEST_SUITE_RUN_BENCHMARKS=ON \
	-DTEST_SUITE_COLLECT_COMPILE_TIME=OFF \
	-DTEST_SUITE_SUBDIRS="$TEST_SUITE_DIR/SingleSource;$TEST_SUITE_DIR/MultiSource" \
	$TEST_SUITE_DIR

Run tests:

$ cd <llvm_test_suite_build_dir> && <llvm_build_dir>/bin/llvm-lit -v --no-progress-bar -o results.json .