Remove assert to enable indexless access chains

Remove assert to accept OpAccessChain without indexes.

Change-Id: Ie57f60d6ac35198e7d7a1b75071fcd985dc1da18
Bug: b/161516333
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/54728
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Presubmit-Ready: Nicolas Capens <nicolascapens@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>
diff --git a/src/Pipeline/SpirvShader.hpp b/src/Pipeline/SpirvShader.hpp
index 44b9e4d..da9cf63 100644
--- a/src/Pipeline/SpirvShader.hpp
+++ b/src/Pipeline/SpirvShader.hpp
@@ -196,7 +196,6 @@
 
 		uint32_t const *wordPointer(uint32_t n) const
 		{
-			ASSERT(n < wordCount());
 			return &iter[n];
 		}