Work around X86 POTRS/CDOT bug on old systems and add CI job for 32bit manylinux #3112

Job	Run time
TEST (I6400, mipsisa64r6el-linux-gnuabi64, NO_SHARED=1 TARGET=I6400)	13m 33s
TEST (P6600, mipsisa64r6el-linux-gnuabi64, NO_SHARED=1 TARGET=P6600)	14m 25s
TEST (I6500, mipsisa64r6el-linux-gnuabi64, NO_SHARED=1 TARGET=I6500)	13m 48s
TEST (SICORTEX, mips64el-linux-gnuabi64, NO_SHARED=1 TARGET=SICORTEX)	13m 49s
TEST (MIPS64_GENERIC, mips64el-linux-gnuabi64, NO_SHARED=1 TARGET=MIPS64_GENERIC)	13m 26s
	1h 9m 1s

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