[llvm] [cmake] Move LLVM_ENABLE_PIC cmake option to HandleLLVMOptions.cmake (PR #84750)

[Saleem Abdulrasool via llvm-commits]

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@@ -376,6 +376,9 @@ if( LLVM_USE_LINKER )
   endif()
 endif()
 
+if (NOT CMAKE_SYSTEM_NAME MATCHES "OS390")
+  option(LLVM_ENABLE_PIC "Build Position-Independent Code" ON)
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compnerd wrote:

This option doesn't really make sense on Windows, it is always PIC.

https://github.com/llvm/llvm-project/pull/84750