LLVM error when using both OpImageSampleDref* and OpImageSample* on the same image

[doitsujin]

Sampling from the same image with both an ordinary texture sampler and a depth-compare sampler causes the shader compiler to fail with the following error:

LLVM ERROR: Error: Attempt to redefine function: 
; Function Attrs: nounwind
declare spir_func %spirv.SampledImage.float_1_1_0_0_1_0_0 addrspace(1)* @_Z12SampledImagePU3AS140__spirv_SampledImage_float_1_0_0_0_1_0_0i(%spirv.SampledImage.float_1_0_0_0_1_0_0 addrspace(1)*, i32) #0
 => %spirv.SampledImage.float_1_0_0_0_1_0_0 addrspace(1)* (%spirv.SampledImage.float_1_0_0_0_1_0_0 addrspace(1)*, i32)

An example shader which triggers the issue can be found here (both disassembled SPIR-V and GLSL):
https://gist.github.com/doitsujin/bfc03c0a432c441426f10f0493c1d4f7

Changing the SPIR-V shader so that the same OpTypeSampledImage is used for both operations fixes the error, although it obviously leads to incorrect results.

[linqun]

Reproduced, we will fix it ASAP.

[linqun]

fixed in dev branch

[jinjianrong]

Fix is merged to master branch