[CMake] Allow for Solaris ld -V output on stdout

[ro]

Summary

In recent versions of Solaris 11.4 (previously 12), ld -V output went to stdout instead
of stderr. Since AddLLVM.cmake only expects it on stderr, Solaris ld wasn't properly
detected and options not understood by it are passed during the build.

The following patch fixes this, allowing for both variants.

Tested on i386-pc-solaris2.11.4 (on top of D35755 which is needed for proper
Solaris support).

[ro]

ping?

[ro]

ping^2

Anyone else who could review this? Thanks.

[mgorny]

I don't see how this could break anything, and it's a pretty straightforward change.

[ro]

Great, thanks. Could you commit it for me?

llvm/trunk/cmake/modules/AddLLVM.cmake

if("${stdout}" MATCHES "GNU gold")
     set(LLVM_LINKER_IS_GOLD ON)
     message(STATUS "Linker detection: GNU Gold")
   elseif("${stdout}" MATCHES "^LLD")
     set(LLVM_LINKER_IS_LLD ON)
     message(STATUS "Linker detection: LLD")
   elseif("${stdout}" MATCHES "GNU ld")
     set(LLVM_LINKER_IS_GNULD ON)
     message(STATUS "Linker detection: GNU ld")
-  elseif("${stderr}" MATCHES "Solaris Link Editors")
+  elseif("${stderr}" MATCHES "Solaris Link Editors" OR
+         "${stdout}" MATCHES "Solaris Link Editors")
     set(LLVM_LINKER_IS_SOLARISLD ON)
     message(STATUS "Linker detection: Solaris ld")
   else()
     set(LLVM_LINKER_DETECTED OFF)
     message(STATUS "Linker detection: unknown")
   endif()
 endif()