i#2666: Decrease MAX_CONTEXT_SIZE for 32-bit to actual value (#4135)
i#2666: Decrease MAX_CONTEXT_SIZE for 32-bit to actual value (#4135)

fb55bf64 over-provisioned the 32-bit context size.  Here we set it to the precise current maximum.

Issue: #2666
AmesianX/dynamorio,AmesianX/dynamorio,AmesianX/dynamorio,AmesianX/dynamorio,AmesianX/dynamorio