[MacPorts] #61789: qt4-mac @4.8.7_10 (aqua): Fails to build on Big Sur w/ arm64 architecture

[MacPorts]

#61789: qt4-mac @4.8.7_10 (aqua): Fails to build on Big Sur w/ arm64 architecture
-----------------------+-----------------------
  Reporter:  maralski  |      Owner:  michaelld
      Type:  defect    |     Status:  assigned
  Priority:  Normal    |  Milestone:
 Component:  ports     |    Version:  2.6.4
Resolution:            |   Keywords:  arm64
      Port:  qt4-mac   |
-----------------------+-----------------------

Comment (by michaelld):

 I finally have an M1 Mac Mini to do live testing on. The addition noted
 above does indeed work, in the sense that on ARM64 / M1, MP cross-builds
 as X86_64. That said, at least on macOS 11.5 20G70 / Xcode 12.3 12C33
 there is 1 compiler error ... and `asm volatile` that is no longer
 accepted by clang. Removing the `volatile` does the trick, so I'm testing
 the patch & will push that once verified. I'm guessing removing that
 keyword will be OK on any ARM64 / M1, so I'm limiting its scope to just
 this situation.

-- 
Ticket URL: <https://trac.macports.org/ticket/61789#comment:10>
MacPorts <https://www.macports.org/>
Ports system for macOS