OpenBLAS @0.3.20: invalid instruction mnemonic on 10.6/10.7

[evanmiller (Evan Miller)]

​https://build.macports.org/builders/ports-10.7_x86_64-builder/builds/94027

/opt/local/var/macports/build/_opt_bblocal_var_buildworker_ports_build_ports_math_OpenBLAS/OpenBLAS/work/compwrap/fc/opt/local/bin/gfortran-mp-11 -Os -m64 -O3 -m128bit-long-double -Wall -frecursive -fno-optimize-sibling-calls -m64 -fPIC -msse3 -mssse3  -c -o sgebak.o sgebak.f
sgebak.f:242:19:

  242 |                K = SCALE( I )
      |                   1
Warning: Possible change of value in conversion from REAL(4) to INTEGER(4) at (1) [-Wconversion]
sgebak.f:256:19:

  256 |                K = SCALE( I )
      |                   1
Warning: Possible change of value in conversion from REAL(4) to INTEGER(4) at (1) [-Wconversion]
/opt/local/var/macports/build/_opt_bblocal_var_buildworker_ports_build_ports_math_OpenBLAS/OpenBLAS/work/.tmp/ccqMKrQL.s:202:2: error: invalid instruction mnemonic 'cvtsi2ssl'
        cvtsi2ssl       %eax, %xmm4
        ^~~~~~~~~
make[2]: *** [sgbrfs.o] Error 1
make[2]: *** Waiting for unfinished jobs....
sgbsvx.f:482:72:

  482 |                COLCND = MAX( RCMIN, SMLNUM ) / MIN( RCMAX, BIGNUM )
      |                                                                        ^
Warning: 'smlnum' may be used uninitialized in this function [-Wmaybe-uninitialized]
sgbsvx.f:482:72: Warning: 'bignum' may be used uninitialized in this function [-Wmaybe-uninitialized]
/opt/local/var/macports/build/_opt_bblocal_var_buildworker_ports_build_ports_math_OpenBLAS/OpenBLAS/work/.tmp/ccxUWghH.s:261:2: error: invalid instruction mnemonic 'cvttss2sil'
        cvttss2sil      (%r12,%rdx,4), %ecx
        ^~~~~~~~~~
/opt/local/var/macports/build/_opt_bblocal_var_buildworker_ports_build_ports_math_OpenBLAS/OpenBLAS/work/.tmp/ccxUWghH.s:343:2: error: invalid instruction mnemonic 'cvttss2sil'
        cvttss2sil      (%r12,%rdx,4), %ecx
        ^~~~~~~~~~
make[2]: *** [sgebak.o] Error 1

[catap (Kirill A. Korinsky)]

In d29ba679d87b8701a00725b6e705d9be09e7e02c/macports-ports (master):

OpenBLAS: fix build on macOS 10.7

Also add myself as co-maintainer

Closes: #67175
Closes: #64973