Reproduction steps:

1. Open "case_TRND-1115-PPSCompileError.zip" project
2. Build for Switch
3. Notice errors in the Console window

Expected Result: No errors appear
Actual Result: Errors appear

Reproduced with: 2017.4.21f1
Did not reproduce on: 2019.2.0b4, 2019.2.0a1, 2019.1.0b4, 2019.1.0a7, 2018.3.7f1, 2018.3.0b9, 2018.2.20f1, 2018.2.5f1

Errors:
Shader error in 'Hidden/PostProcessing/Uber': Vertex shader compilation failed.
Shader error in 'Hidden/PostProcessing/FinalPass': Vertex shader compilation failed.

Shader info log:
_shader1544178020(26) : error C0000: ... or #extension GL_NV_viewport_array2 : enable
_shader1544178020(26) : error C0000: ... or #extension GL_AMD_vertex_shader_layer : enable
(on switch)

Compiling Vertex program with STEREO_INSTANCING_ENABLED FXAA_KEEP_ALPHA
Platform defines: UNITY_ENABLE_REFLECTION_BUFFERS UNITY_USE_DITHER_MASK_FOR_ALPHABLENDED_SHADOWS UNITY_PBS_USE_BRDF1 UNITY_SPECCUBE_BOX_PROJECTION UNITY_SPECCUBE_BLENDING UNITY_ENABLE_DETAIL_NORMALMAP UNITY_COLORSPACE_GAMMA UNITY_LIGHTMAP_RGBM_ENCODING