Bug 89971 [Viewers] Viewers that use IViewerLabelProvider do too many instanceof checks
M6 Checking our viewer the calls to buildLabel are doing too many instanceof checks. As a result certain viewers (such as the table viewer) are twice as slow as they were in 3.0 due to these checks. I have written some performance suites to test the Table, Tree, List and Combo viewers. Table and Tree have this issue.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
* @param provider IBaseLabelProvider
		 * @see IColorProvider
		 * @see IFontProvider
		 */
		public ColorAndFontCollector(IBaseLabelProvider provider) {
			if (provider instanceof IColorProvider)
				colorProvider = (IColorProvider) provider;
			if (provider instanceof IFontProvider)
				fontProvider = (IFontProvider) provider;
		}
		
		/**
		 * Create a new instance of the receiver with
		 * no colour and font provider.	
		 */
		public ColorAndFontCollector(){
			
		}
		/**
		 * Clear all of the results.
		 */
		public void clear() {
			foreground = null;
			background = null;
			font = null;
			usedDecorators = false;
		}
		
		/**
		 * Set the initial fonts and colors for the element from the