Fixed some test cases that were failing

platforms/cuda/src/CudaContext.cpp

@@ -77,6 +77,7 @@ CudaContext::CudaContext(const System& system, int deviceIndex, bool useBlocking
         time(0.0), platformData(platformData), stepCount(0), computeForceCount(0), stepsSinceReorder(99999), contextIsValid(false), atomsWereReordered(false), hasCompilerKernel(false),
         pinnedBuffer(NULL), posq(NULL), posqCorrection(NULL), velm(NULL), force(NULL), energyBuffer(NULL), integration(NULL), expression(NULL), bonded(NULL), nonbonded(NULL), thread(NULL) {
     this->compiler = "\""+compiler+"\"";
+    if (platformData.context != NULL) {
         try {
             compilerKernel = platformData.context->getPlatform().createKernel(CudaCompilerKernel::Name(), *platformData.context);
             hasCompilerKernel = true;
@@ -84,6 +85,7 @@ CudaContext::CudaContext(const System& system, int deviceIndex, bool useBlocking
         catch (...) {
             // The runtime compiler plugin isn't available.
         }
+    }
     if (hostCompiler.size() > 0)
         this->compiler = compiler+" --compiler-bindir "+hostCompiler;
     if (!hasInitializedCuda) {