How to reproduce:
1. Open the tester-attached project(case_1281069-il2cpp_nested_trycatch_bug.zip)
2. Open the build settings window(File > Build Settings)
3. In Player Settings change the scripting backend to Mono(can be left as IL2CPP if an appropriate module is installed)
4. Start building the player by clicking the 'Build' button
5. Once the progress is more than halfway finished, cancel the build
6. See the Console window. If nothing is thrown, repeat from step 4(may take up to 3-4 tries)

Expected result: no warnings/errors are thrown
Actual: Allocation of N bytes at [Memory Address] logs are spammed in the Console. This eventually may lead to a crash

Reproducible with: 2019.3.0f6, 2019.4.15f1, 2020.1.0a21, 2020.1.15f1, 2020.2.0b13, 2021.1.0a8
Not reproducible with: 2018.4.29f1, 2019.3.0f5, 2020.1.0a1, 2020.1.0a20

Notes:
Reproduced on Windows and MacOS

Errors:
TLS Allocator ALLOC_TEMP_THREAD, underlying allocator ALLOC_TEMP_THREAD has unfreed allocations, size N

Warnings:
Internal: Stack allocator ALLOC_TEMP_THREAD has unfreed allocations, size N
To Debug, enable the define: DEBUG_STACK_LEAK in StackAllocator.h. This will output the callstacks of the leaked allocations