LoongArch: Add tests for SX vector vfcmp instructions.
gcc/testsuite/ChangeLog:
* gcc.target/loongarch/vector/lsx/lsx-vfcmp_caf.c: New test.
* gcc.target/loongarch/vector/lsx/lsx-vfcmp_ceq.c: New test.
* gcc.target/loongarch/vector/lsx/lsx-vfcmp_cle.c: New test.
* gcc.target/loongarch/vector/lsx/lsx-vfcmp_clt.c: New test.
* gcc.target/loongarch/vector/lsx/lsx-vfcmp_cne.c: New test.
* gcc.target/loongarch/vector/lsx/lsx-vfcmp_cor.c: New test.
* gcc.target/loongarch/vector/lsx/lsx-vfcmp_cun.c: New test.
* gcc.target/loongarch/vector/lsx/lsx-vfcmp_saf.c: New test.
* gcc.target/loongarch/vector/lsx/lsx-vfcmp_seq.c: New test.
* gcc.target/loongarch/vector/lsx/lsx-vfcmp_sle.c: New test.
* gcc.target/loongarch/vector/lsx/lsx-vfcmp_slt.c: New test.
* gcc.target/loongarch/vector/lsx/lsx-vfcmp_sne.c: New test.
* gcc.target/loongarch/vector/lsx/lsx-vfcmp_sor.c: New test.
* gcc.target/loongarch/vector/lsx/lsx-vfcmp_sun.c: New test.