Enable cling to be built with Emscripten

Author: mcbarton

interpreter/cling/CMakeLists.txt

@@ -118,7 +118,7 @@ else()
   endif()
 endif()
 
-if( NOT "NVPTX" IN_LIST LLVM_TARGETS_TO_BUILD)
+if( NOT "NVPTX" IN_LIST LLVM_TARGETS_TO_BUILD AND NOT EMSCRIPTEN)
   message(FATAL_ERROR "NVPTX backend is not activated\n"
     "Please enable it via -DLLVM_TARGETS_TO_BUILD=\"host;NVPTX\"")
 endif()

interpreter/cling/lib/Interpreter/IncrementalCUDADeviceCompiler.cpp

@@ -92,13 +92,13 @@ namespace cling {
       llvm::errs() << "Could not create PTX interpreter instance\n";
       return;
     }
-
+#ifndef __EMSCRIPTEN__
     // initialize NVPTX backend
     LLVMInitializeNVPTXTargetInfo();
     LLVMInitializeNVPTXTarget();
     LLVMInitializeNVPTXTargetMC();
     LLVMInitializeNVPTXAsmPrinter();
-
+#endif
     m_Init = true;
   }