How to reproduce:
1. Create a new project (or simply open the attached project 'test-standart-shader.zip' and skip to step 6)
2. In the Hierarchy window create a new Cube
3. Go to Edit -> Project Settings -> Graphics and under the 'Always Included Shaders' setting add the 'Standard' Shader as another element
4. Open the ProjectSettings.asset in a text editor and change the webGLMemorySize setting to 128
5. Change the 'webGLEmscriptenArgs' setting like so 'webGLEmscriptenArgs: -s ALLOW_MEMORY_GROWTH=0 -s TOTAL_MEMORY=134217728'
6. Back in Unity go to File -> Build Settings and switch the platform to WebGL
7. Add the 'SampleScene' to the build order and click 'Build And Run'

Reproducible with: 2018.4.32f1, 2019.4.21f1, 2020.2.7f1, 2021.1.0b10, 2021.2.0a6

Notes:
- This error message is thrown in the browser (2020.2, 2021.1, 2021.2): 'abort("Cannot enlarge memory arrays. Either (1) compile with -s TOTAL_MEMORY=X with X higher than the current value 134217728, (2) compile with -s ALLOW_MEMORY_GROWTH=1 which allows increasing the size at runtime, or (3) if you want malloc to return NULL (0) instead of this abort, compile with -s ABORTING_MALLOC=0'
- This error message is thrown in the browser (2018.4, 2019.4): 'Out of memory. If you are the developer of this content, try allocating more memory to your WebGL build in the WebGL player settings'