Fixes for some gcc warnings #5919

Job	Run time
build (ubuntu-latest, flang, make)	18m 53s
build (ubuntu-latest, gfortran, make)	21m 22s
build (macos-latest, gfortran, cmake)	30m 17s
neoverse_build	7m 35s
msys2 (UCRT64, int64, Release)	1h 39m 38s
msys2 (UCRT64, int32, Release)	1h 39m 30s
build (ubuntu-latest, gfortran, cmake)	45m 40s
build (macos-latest, gfortran, make)	3m 21s
build (ubuntu-latest, flang, cmake)	45m 10s
msys2 (MINGW32, int32, Release)	1h 6m 13s
msys2 (UCRT64, int32, None, mingw-w64-ucrt-x86_64, fc)	11m 49s
msys2 (CLANG64, int64, Release)	1h 9m 0s
cross_build (riscv64, riscv64-linux-gnu, TARGET=RISCV64_GENERIC)	2m 40s
cross_build (mips64el, mips64el-linux-gnuabi64, DYNAMIC_ARCH=1 TARGET=GENERIC)	3m 26s
cross_build (alpha, alpha-linux-gnu, TARGET=EV4)	7m 34s
cross_build (mipsel, mipsel-linux-gnu, TARGET=MIPS1004K)	3m 21s
msys2 (CLANG64, int32, Release)	15m 27s
	9h 10m 56s

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