Fix NPE in MinimalState when project VM install is null

   JavaRuntime.getVMInstall() can return null during project setup.
   The null was passed to ExecutionEnvironment.isStrictlyCompatible()
   which uses ConcurrentHashMap.containsKey(null), causing NPE.

   This crashed the Plug-in Manifest Builder, leaving workspace projects
   in inconsistent state and causing cascading test failures in
   ProjectSmartImportTest.

Author: laeubi

ui/org.eclipse.pde.core/src/org/eclipse/pde/internal/core/MinimalState.java

@@ -162,6 +162,11 @@ private Map<String, String> loadWorkspaceBundleManifest(File bundleLocation, IRe
 			return manifest;
 		}
 		IVMInstall projectVmInstall = JavaRuntime.getVMInstall(javaProject);
+		if (projectVmInstall == null) {
+			PDECore.log(Status.warning("Could not determine VM install for project " //$NON-NLS-1$
+					+ resource.getProject().getName() + ", skipping BREE injection")); //$NON-NLS-1$
+			return manifest;
+		}
 
 		IExecutionEnvironment executionEnvironment = Arrays
 				.stream(JavaRuntime.getExecutionEnvironmentsManager().getExecutionEnvironments())