Fix redundant decorations in IRParam (shader-slang#4964)

* Fix redundant decorations in IRParam

Closes shader-slang#4922

The problem was that same decorations were added to an IRParam multiple
times while running `specializeIRForEntryPoint()`.

`cloneGlobalValueWithCodeCommon()` kept cloning decorations for the
params that were already processed.

Author: jkwak-work

source/slang/slang-ir-link.cpp

@@ -751,9 +751,9 @@ void cloneGlobalValueWithCodeCommon(
             IRParam* originalParam;
             IRParam* clonedParam;
         };
-        ShortList<ParamCloneInfo> paramCloneInfos;
         while (ob)
         {
+            ShortList<ParamCloneInfo> paramCloneInfos;
             SLANG_ASSERT(cb);
 
             builder->setInsertInto(cb);

tests/bugs/gh-4922-nointerpolation.slang

@@ -0,0 +1,15 @@
+//TEST:SIMPLE(filecheck=HLSL): -target hlsl -entry main
+//TEST:SIMPLE(filecheck=GLSL): -target glsl -entry main
+
+// This test checks if `nointerpolation` is emitted more than once
+//HLSL-NOT:nointerpolation nointerpolation 
+//GLSL-NOT:flat flat
+
+[shader("pixel")]
+void main(out float4 SV_Target : SV_Target, const in nointerpolation float4 color : color)
+{
+    for (int i = 0; i < 10; ++i)
+    {}
+
+    SV_Target = color;
+}