Steps to reproduce:

1) Download attached project 'UnityGLSLBug-Unity522.zip'
2) Build and run 'TestingGLES' scene on a devcie
Note: shader will fail to compile (sphere in a scene will be pink)

Expected result: Shader will be compiled without any issue (check attached image 'expected.png')
Actual result: GLSL shader compilation failure (check attached image 'actual.png')

Regression from:
5.6.0b3

Reproduced with:
5.6.0b3, 5.6.0f3, 2017.1.0b1

Not reproduced with:
5.5.3p1, 5.6.0b2

DUT:

Reproduced with:
GLES2 and GLES3

iPhone 6S iOS10.3

Samsung SM G925F (Galaxy S6 Edge), OS:6.0.1, CPU:arm64-v8a, GPU:Mali-T760, Build:samsung/zeroltexx/zerolte:6.0.1/MMB29K/G925FXXU5DQA7:user/release-keys

Samsung GT N7100 (Galaxy Note 2), OS:4.4.2, CPU:armeabi-v7a, GPU:Mali-400 MP, Build:samsung/t03gxx/t03g:4.4.2/KOT49H/N7100XXUFNE1:user/release-keys

Not reproduced with:

Sony D6603 (Xperia Z3), OS:6.0.1, CPU:armeabi-v7a, GPU:Adreno (TM) 330, Build:Sony/D6603/D6603:5.1.1/23.4.A.1.264/2418263178:user/release-keys

Verizon SM G930V (Galaxy S7 Verizon), OS:7.0, CPU:arm64-v8a, GPU:Adreno (TM) 530, Build:Verizon/heroqltevzw/heroqltevzw:7.0/NRD90M/G930VVRU4BQA2:user/release-keys