[Backport] 8290496: riscv: Fix build warnings-as-errors with GCC 11 #21

Job	Run time
Prerequisites / Prerequisites	43s
Prerequisites / Check Commit Message	0s
linux-aarch64 / build (debug)	1s
linux-aarch64 / build (release)	1s
riscv64 / build (release)	1s
windows-x64 / build (debug)	40m 41s
linux-x64 / build (debug)	26m 39s
windows-x64 / build (release)	35m 45s
linux-x64 / build (release)	23m 25s
linux-x64 / test (jdk/tier1 part 1)	11m 12s
linux-x64 / test (jdk/tier1 part 2)	10m 27s
linux-x64 / test (jdk/tier1 part 3)	4m 50s
linux-x64 / test (langtools/tier1)	19m 26s
linux-x64 / test (hs/tier1 common)	2m 7s
linux-x64 / test (hs/tier1 compiler)	22m 1s
linux-x64 / test (hs/tier1 gc)	22m 16s
linux-x64 / test (hs/tier1 runtime)	6m 49s
linux-x64 / test (hs/tier1 serviceability)	3m 34s
linux-x64 / test (dragonwell/hs feature)	5m 22s
linux-x64 / test (dragonwell/jdk feature)	4m 59s
windows-x64 / test (jdk/tier1 part 1)	21m 26s
windows-x64 / test (jdk/tier1 part 2)	17m 37s
windows-x64 / test (jdk/tier1 part 3)	9m 7s
windows-x64 / test (langtools/tier1)	2s
windows-x64 / test (hs/tier1 common)	5m 28s
windows-x64 / test (hs/tier1 compiler)	3s
windows-x64 / test (hs/tier1 gc)	4s
windows-x64 / test (hs/tier1 runtime)	4s
windows-x64 / test (hs/tier1 serviceability)	4s
windows-x64 / test (dragonwell/hs feature)	2s
windows-x64 / test (dragonwell/jdk feature)	3s
linux-aarch64	0s
Remove bundle artifacts	0s
	4h 54m 19s

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