Add generated LA64 test cases

[CSharperMantle]

This PR adds LA64 tests generated by https://gist.github.com/CSharperMantle/7a6615aa2cfcfcf7ce344816db2dc5b3#file-gen_test-py. This covers all instruction mnemonics, with 10 cases for each instruction.

This test matches the output of:

$ loongarch64-linux-gnu-objdump -b binary -m Loongarch64 -D --no-addresses --show-raw-insn --disassembler-options=no-aliases ./tests.bin

Preferred merge strategy: Squash.

Context

I generated tests by identifying the variable parts of every Instruction, and generating a couple of random bit patterns I could then decode with objdump (or whatever decompiler you want the instructions to match), parse the result and create the tests that way.

Originally posted by @FRoith in #33 (comment)

[CSharperMantle]

The current test generator creates duplicated entries for instructions with less than 10 variants.

instruction-decoder/test_data/la64/la64.test

Lines 1962 to 1971 in b65a19d

	06483800 ertn
	06483800 ertn
	06483800 ertn
	06483800 ertn
	06483800 ertn
	06483800 ertn
	06483800 ertn
	06483800 ertn
	06483800 ertn
	06483800 ertn

A fix is underway.

---

Update: Done.

[FRoith]

looks good!