Improve startup performance

[manodasanW]

• Reduce use of linq expressions and replace them with reflection as our uses of linq expressions were found to have a significant initial cost possibly due to its internal initialization which the replacements don't seem to have. In addition, comparing the over time performance after the initial call with some scenarios don't seem to show a regression in performance.
• Reorder the logic in GUID generation in order of expense to avoid unnecessary cost.
• For IsIReferenceArray, do a type check instead of full name check as the full name cost was showing up in traces and type checks should be faster.
• Improve the generic nullable scenario to reduce allocating objects and reduce the time spent jitting different generic versions of nullable.
• As part of our lazy replacement, we generated Make functions along with properties to retrieve them. These were also done for the ones which reuse inner as is when they were not needed. Removing those and making those properties directly refer to inner instead.
• Replace a couple more .Guid calls which were showing up on traces as GetCustomAttribute calls with equivalent hard coded values.