Remove unneeded assert (#5256)

When processing the dot intrinsic, there is an assert that ensure the
return type is the same as the componentent type of the operands. This
is not true when the types were originally half. At that point, the
operands will have been promoted to float, but the return type will be
promoted later.

Since the assert is not universally true, I will remove it.

Fixes #5048

tools/clang/lib/SPIRV/SpirvEmitter.cpp

@@ -10318,8 +10318,7 @@ SpirvInstruction *SpirvEmitter::processIntrinsicDot(const CallExpr *callExpr) {
   assert(arg0isScalarOrVec && arg1isScalarOrVec);
   // The result type must be a scalar.
   assert(returnIsScalar);
-  // The element type of each argument and the return type must be the same.
-  assert(returnType == vec1ComponentType);
+  // The element type of each argument must be the same.
   assert(vec0ComponentType == vec1ComponentType);
   // The size of the two arguments must be equal.
   assert(vec0Size == vec1Size);

tools/clang/test/CodeGenSPIRV/intrinsics.dot.hlsl

@@ -164,4 +164,10 @@ void main() {
     // CHECK-NEXT: OpDot %float
     float3 f3;
     float dotProductByLiteral = dot(f3, float3(1.0.xxx));
+   
+    // A dot product using `half` should get promoted to `float`. 
+    // CHECK:      OpCompositeConstruct %v3float %float_1 %float_1 %float_1
+    // CHECK-NEXT: OpDot %float
+    half3 h3;
+    half dotProductWithHalf = dot(h3, half3(1.0.xxx));
 }