SpirvShaderDebugger: Improve ASSERT() messages
SpirvShaderDebugger: Improve ASSERT() messages

DXC is producing duplicate definitions for local variables.
Give more context in the `ASSERT()` so it's easier to diagnose whats going wrong.

Bug: b/170378370
Change-Id: Ic8c8f24a6dbd8ce23e04eb4f0265363b44bc174c
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/49128
Kokoro-Result: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
Reviewed-by: Nicolas Capens <51edc787c30f24c4904e8ffbb5523c3a9f7a451d@google.com>
Tested-by: Ben Clayton <1f693eb7158dc33015048c09d6712f74dabddf79@google.com>

bkaradzic/SwiftShader,google/swiftshader,google/swiftshader,bkaradzic/SwiftShader,bkaradzic/SwiftShader,bkaradzic/SwiftShader,google/swiftshader,bkaradzic/SwiftShader