Approximation of tree incrementality for Z3 solver #780

Job	Run time
Coverage (STP)	39m 24s
Coverage (Z3)	40m 8s
Docker	10m 25s
Linux (LLVM 14)	8m 1s
Linux (LLVM 13)	8m 1s
Linux (LLVM 12)	8m 0s
Linux (LLVM 11, Doxygen)	8m 0s
Linux (LLVM 10)	8m 1s
Linux (LLVM 9)	8m 1s
Linux (ASan)	8m 2s
Linux (UBSan)	1s
Linux (MSan)	6m 56s
Linux (Z3 only)	1s
Linux (metaSMT)	7m 43s
Linux (STP master)	2m 50s
Linux (Latest klee-uclibc)	8m 3s
Linux (Asserts disabled)	8m 4s
Linux (No TCMalloc, optimised runtime)	3m 33s
clang-format	5m 5s
macOS	11m 27s
	3h 19m 46s

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