Remove -Wl,-z,defs linker flag when building shared libraries using llvm with emscripten

Co-Authored-By: Vassil Vassilev <[email protected]>

Author: mcbarton

llvm/cmake/modules/HandleLLVMOptions.cmake

@@ -309,15 +309,13 @@ if(${CMAKE_SYSTEM_NAME} MATCHES "AIX")
     message(WARNING "Build and install environment path info may be exposed; binaries will also be unrelocatable.")
   endif()
 endif()
-
 # Pass -Wl,-z,defs. This makes sure all symbols are defined. Otherwise a DSO
 # build might work on ELF but fail on MachO/COFF.
-if(NOT (CMAKE_SYSTEM_NAME MATCHES "Darwin|FreeBSD|OpenBSD|DragonFly|AIX|OS390" OR
+if(NOT (CMAKE_SYSTEM_NAME MATCHES "Darwin|FreeBSD|OpenBSD|DragonFly|AIX|OS390|Emscripten" OR
         WIN32 OR CYGWIN) AND
    NOT LLVM_USE_SANITIZER)
   set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,-z,defs")
 endif()
-
 # Pass -Wl,-z,nodelete. This makes sure our shared libraries are not unloaded
 # by dlclose(). We need that since the CLI API relies on cross-references
 # between global objects which became horribly broken when one of the libraries