[FIR] Save IR dumps to .ir.txt files instead of .txt in tests

This is needed to avoid clashes between different dumps from different
  handlers

compiler/testData/ir/irText/declarations/parameters/class.kt.txt

@@ -31,4 +31,3 @@ class Test<T0 : Any?> {
   }
 
 }
-

compiler/testData/ir/irText/declarations/parameters/constructor.kt.txt

@@ -78,4 +78,3 @@ class Test4<T : Any?> {
   }
 
 }
-

compiler/testData/ir/irText/declarations/parameters/dataClassMembers.kt.txt

@@ -56,4 +56,3 @@ data class Test<T : Any?> {
   }
 
 }
-

compiler/testData/ir/irText/declarations/parameters/defaultPropertyAccessors.kt.txt

@@ -42,4 +42,3 @@ class InPrimaryCtor<T : Any?> {
     set
 
 }
-

compiler/testData/ir/irText/declarations/parameters/fun.kt.txt

@@ -24,4 +24,3 @@ class Host {
   }
 
 }
-

compiler/testData/ir/irText/declarations/parameters/genericInnerClass.kt.txt

@@ -18,4 +18,3 @@ class Outer<T1 : Any?> {
   }
 
 }
-

compiler/testData/ir/irText/declarations/parameters/lambdas.kt.txt

@@ -24,4 +24,3 @@ val test4: Function2<Int, Int, Unit>
   }
 
   get
-

compiler/testData/ir/irText/declarations/parameters/localFun.kt.txt

@@ -12,4 +12,3 @@ fun <TT : Any?> outer() {
   }
 
 }
-

compiler/testData/ir/irText/declarations/parameters/propertyAccessors.kt.txt

@@ -78,4 +78,3 @@ class Host<T : Any?> {
     }
 
 }
-

compiler/testData/ir/irText/declarations/parameters/typeParameterBeforeBound.kt.txt

@@ -15,4 +15,3 @@ var <T : U, U : Any?> Test1<T, U>.test3: Unit
   }
   set(value: Unit) {
   }
-

compiler/testData/ir/irText/declarations/parameters/typeParameterBoundedBySubclass.kt.txt

@@ -36,4 +36,3 @@ class Derived2 : Base2 {
   }
 
 }
-

compiler/testData/ir/irText/declarations/parameters/useNextParamInLambda.kt.txt

@@ -25,4 +25,3 @@ fun box(): String {
   }
 ))
 }
-