compilers: blacklist llvm from :openmp
compilers: blacklist llvm from :openmp

Closes Homebrew/homebrew#38912.

Signed-off-by: Mike McQuaid <a17fed27eaa842282862ff7c1b9c8395a26ac320@mikemcquaid.com>

pseudocody/brew,gregory-nisbet/brew,vitorgalvao/brew,Homebrew/brew,tonyg/homebrew,Homebrew/brew,gordonmcshane/homebrew,ilovezfs/brew,EricFromCanada/brew,zmwangx/brew,staticfloat/brew,EricFromCanada/brew,reitermarkus/brew,reitermarkus/brew,palxex/brew,maxim-belkin/brew,gregory-nisbet/brew,claui/brew,bfontaine/brew,DomT4/brew,nandub/brew,aw1621107/brew,JCount/brew,bfontaine/brew,JCount/brew,ilovezfs/brew,mistydemeo/homebrew,staticfloat/brew,vitorgalvao/brew,tonyg/homebrew,gordonmcshane/homebrew,muellermartin/dist,aw1621107/brew,mistydemeo/homebrew,palxex/brew,mgrimes/brew,hanxue/linuxbrew,sjackman/homebrew,mahori/brew,reelsense/brew,AnastasiaSulyagina/brew,Linuxbrew/brew,Linuxbrew/brew,gregory-nisbet/brew,reelsense/brew,konqui/brew,palxex/brew,MikeMcQuaid/brew,alyssais/brew,pseudocody/brew,mahori/brew,tonyg/homebrew,MikeMcQuaid/brew,mgrimes/brew,mahori/brew,alyssais/brew,DomT4/brew,amar-laksh/brew_sudo,staticfloat/brew,aw1621107/brew,nandub/brew,reitermarkus/brew,zmwangx/brew,Linuxbrew/brew,sjackman/homebrew,toonetown/homebrew,hanxue/linuxbrew,ilovezfs/brew,alyssais/brew,amar-laksh/brew_sudo,AnastasiaSulyagina/brew,muellermartin/dist,sjackman/homebrew,mistydemeo/homebrew,Homebrew/brew,rwhogg/brew,pseudocody/brew,bfontaine/brew,claui/brew,jmsundar/brew,Linuxbrew/brew,maxim-belkin/brew,mahori/brew,toonetown/homebrew,konqui/brew,hanxue/linuxbrew,vitorgalvao/brew,amar-laksh/brew_sudo,reitermarkus/brew,DomT4/brew,sjackman/homebrew,EricFromCanada/brew,rwhogg/brew,DomT4/brew,jmsundar/brew,MikeMcQuaid/brew,nandub/brew,mgrimes/brew,zmwangx/brew,claui/brew,jmsundar/brew,muellermartin/dist,gordonmcshane/homebrew,toonetown/homebrew,vitorgalvao/brew,MikeMcQuaid/brew,rwhogg/brew,Homebrew/brew,konqui/brew,JCount/brew,claui/brew,nandub/brew,konqui/brew,EricFromCanada/brew,reelsense/brew,AnastasiaSulyagina/brew,maxim-belkin/brew,JCount/brew