graphics/raster3d: Unbreak build with GCC 10

render.f:971:28:

971 |  BKGND(3) = iand(XBG,X'00FF')
    |                            1

Error: Hexadecimal constant at (1) uses nonstandard X instead of Z [see '-fno-allow-invalid-boz']
render.f:972:28:

972 |  BKGND(2) = iand(XBG,X'FF00')/256
    |                            1

Error: Hexadecimal constant at (1) uses nonstandard X instead of Z [see '-fno-allow-invalid-boz']
render.f:973:28:

973 |  BKGND(1) = iand(XBG,X'FF0000')/65536
    |                            1

Error: Hexadecimal constant at (1) uses nonstandard X instead of Z [see '-fno-allow-invalid-boz']

Error: More actual than formal arguments in procedure call at (1)
render.f:1079:22:

1077 | IERR = LOCAL(5, IBKGND(1), IBKGND(2), IBKGND(3))

|                      2

1078 | IERR = LOCAL(1, NAX, NAY, OTMODE, QUALITY)
1079 | IERR = LOCAL(4, TITLE)

|                      1

Error: Type mismatch between actual argument at (1) and actual argument at (2) (CHARACTER(132)/INTEGER(4)).
render.f:4402:22:

1077 | IERR = LOCAL(5, IBKGND(1), IBKGND(2), IBKGND(3))

|                      2

......
4402 | IERR = LOCAL(2, OUTBUF(K+1,1), OUTBUF(K+1,2), OUTBUF(K+1,3),

|                      1

Error: Type mismatch between actual argument at (1) and actual argument at (2) (INTEGER(2)/INTEGER(4)).
render.f:4430:13:

4430 | IERR = LOCAL(3)

|             1

Error: Missing actual argument for argument '_formal_4' at (1)

http://package18.nyi.freebsd.org/data/121amd64-default-PR244494/2020-06-10_18h04m44s/logs/errors/raster3d-3.0.3_7.log

PR: 246700