mtvec_handler aligment

[MarekPesta]

In riscv_test.h there is a weak mtvec_handler declaration aligned to 6.
https://github.com/riscv/riscv-test-env/blob/4fabfb4e0d3eacc1dc791da70e342e4b68ea7e46/p/riscv_test.h#L170

However, in illegal.S test, mtvec_handler is aligned to 8. Shouldn't this be consistent?

riscv-tests/isa/rv64mi/illegal.S

Line 132 in 0ab6b90

.align 8

This difference in .align values determines that for the illegal.S test the _start symbol has a value of .align 8, while for tests that do not implement mtvec_handler the same symbol has a value of .align 6. This can lead to problems in simpler systems with a fixed starting point value.