Cranelift: riscv64: fix instruction worst-case-length checks. #10555
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In bytecodealliance#10502, we introduced changes that could make callsites be arbitrarily long, because they now include loads of return-values-on-stack. We made use of the existing island mechanism (now presented as a new pseudoinst as in aarch64, rather than as ad-hoc emission code) to ensure that we meet label-reference-distance deadlines. Unfortunately we didn't update the debug-assert that checks instructions for worst-case size to exclude calls (and the new `EmitIsland` pseudoinst), since they handle islanding separately. Found via fuzzbug at [1]. [1]: https://oss-fuzz.com/testcase-detail/4819793142415360
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In #10502, we introduced changes that could make callsites be arbitrarily long, because they now include loads of return-values-on-stack. We made use of the existing island mechanism (now presented as a new pseudoinst as in aarch64, rather than as ad-hoc emission code) to ensure that we meet label-reference-distance deadlines. Unfortunately we didn't update the debug-assert that checks instructions for worst-case size to exclude calls (and the new
EmitIslandpseudoinst), since they handle islanding separately.Found via fuzzbug at 1.