Fully qualify the offset type in FLATBUFFERS_VTABLE_UNDERLYING_TYPE (… #5575

Job	Run time
Build Benchmarks (on Linux) (g++-10)	4m 58s
Build Android (on Linux)	5m 3s
Build Dart	2m 5s
Build .NET Windows	2m 11s
Build .NET Windows (-p:UnsafeByteBuffer=true)	1m 54s
Check Generated Code (g++-10)	1m 38s
Check Generated Code (clang++-12)	1m 43s
Check Generated Code on Windows	6m 21s
Build Go	2m 6s
Build Java	21s
Build Kotlin Linux	3m 11s
Build Kotlin MacOS	5m 11s
Build Linux (g++-10)	2m 42s
Build Linux (clang++-12)	2m 52s
Build Linux C++ (11, g++-10)	3m 17s
Build Linux C++ (11, clang++-12)	2m 45s
Build Linux C++ (14, g++-10)	2m 47s
Build Linux C++ (14, clang++-12)	3m 58s
Build Linux C++ (17, g++-10)	4m 1s
Build Linux C++ (17, clang++-12)	3m 18s
Build Linux C++ (20, g++-10)	3m 42s
Build Linux C++ (20, clang++-12)	2m 28s
Build Linux C++ (23, clang++-12)	2m 54s
Build Linux with -DFLATBUFFERS_NO_FILE_TESTS	2m 44s
Build Linux with out-of-source build location	2m 0s
Build Mac (for Intel)	2m 46s
Build Mac (universal build)	4m 58s
Build Nim	1m 50s
Build PHP	1m 47s
Build Python	1m 42s
Build Rust Linux	2m 55s
Build Rust Windows	3m 55s
Build Swift	2m 17s
Build Swift Wasm	2m 17s
Build TS	2m 10s
Build Windows 2019	6m 20s
Build Windows 2015	6m 33s
Build Windows 2017	6m 23s
Build Windows C++ (11)	5m 17s
Build Windows C++ (14)	5m 15s
Build Windows C++ (17)	7m 12s
Build Windows C++ (20)	8m 37s
Build Windows C++ (23)	7m 57s
release-digests	0s
provenance	0s
	2h 36m 21s

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