[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/expressions/floatingPointComparisons/comparableWithDoubleOrFloat.kt.txt

@@ -17,4 +17,3 @@ fun testF(x: Comparable<Float>, y: Comparable<Float>): Boolean {
     else -> false
   }
 }
-

compiler/testData/ir/irText/expressions/floatingPointComparisons/eqeqRhsConditionPossiblyAffectingLhs.kt.txt

@@ -4,4 +4,3 @@ fun test(x: Any): Boolean {
     else -> x /*as Double */
   })
 }
-

compiler/testData/ir/irText/expressions/floatingPointComparisons/floatingPointCompareTo.kt.txt

@@ -77,4 +77,3 @@ fun Float.test3fr(x: Any): Boolean {
     else -> false
   }
 }
-

compiler/testData/ir/irText/expressions/floatingPointComparisons/floatingPointEqeq.kt.txt

@@ -83,4 +83,3 @@ fun testDF(x: Any, y: Any): Boolean {
     else -> false
   }
 }
-

compiler/testData/ir/irText/expressions/floatingPointComparisons/floatingPointEquals.kt.txt

@@ -113,4 +113,3 @@ fun Float.test6fr(x: Any): Boolean {
     else -> false
   }
 }
-

compiler/testData/ir/irText/expressions/floatingPointComparisons/floatingPointExcleq.kt.txt

@@ -83,4 +83,3 @@ fun testDF(x: Any, y: Any): Boolean {
     else -> false
   }
 }
-

compiler/testData/ir/irText/expressions/floatingPointComparisons/floatingPointLess.kt.txt

@@ -59,4 +59,3 @@ fun testDF(x: Any, y: Any): Boolean {
     else -> false
   }
 }
-

compiler/testData/ir/irText/expressions/floatingPointComparisons/nullableAnyAsIntToDouble.kt.txt

@@ -4,4 +4,3 @@ fun test(x: Any?, y: Double): Boolean {
     else -> false
   }
 }
-

compiler/testData/ir/irText/expressions/floatingPointComparisons/nullableFloatingPointEqeq.kt.txt

@@ -43,4 +43,3 @@ fun testDI2(x: Any?, y: Any?): Boolean {
     else -> false
   }
 }
-

compiler/testData/ir/irText/expressions/floatingPointComparisons/typeParameterWithPrimitiveNumericSupertype.kt.txt

@@ -62,4 +62,3 @@ class F<T : Float> {
   }
 
 }
-

compiler/testData/ir/irText/expressions/floatingPointComparisons/whenByFloatingPoint.fir.kt.txt

@@ -77,4 +77,3 @@ fun testWithPrematureExitInConditionSubexpression(x: Any): Int {
     }
   }
 }
-

compiler/testData/ir/irText/expressions/floatingPointComparisons/whenByFloatingPoint.kt.txt

@@ -77,4 +77,3 @@ fun testWithPrematureExitInConditionSubexpression(x: Any): Int {
     }
   }
 }
-