Add test for SHGEMM #6200

Job	Run time
msys2 (MINGW32, int32, Release)	15m 58s
msys2 (UCRT64, int64, Release)	1h 44m 32s
build (ubuntu-latest, gfortran, make)	24m 7s
msys2 (CLANG64, int32, Release)	18m 24s
msys2 (UCRT64, int32, Release)	1h 46m 25s
build (ubuntu-latest, flang, make)	19m 6s
build (ubuntu-latest, gfortran, cmake)	45m 30s
msys2 (CLANG64, int64, Release)	1h 15m 46s
cross_build (mips64el, mips64el-linux-gnuabi64, DYNAMIC_ARCH=1 TARGET=GENERIC)	5m 11s
cross_build (riscv64, riscv64-linux-gnu, TARGET=RISCV64_GENERIC)	2m 50s
cross_build (mipsel, mipsel-linux-gnu, TARGET=MIPS1004K)	9m 11s
build (ubuntu-latest, flang, cmake)	45m 8s
msys2 (UCRT64, int32, None, mingw-w64-ucrt-x86_64, fc)	1h 34m 54s
cross_build (alpha, alpha-linux-gnu, TARGET=EV4)	4m 50s
build (macos-latest, gfortran, cmake)	21m 31s
build (macos-latest, gfortran, make)	5m 16s
neoverse_build	8m 20s
	10h 6m 59s

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