[fir] Remove unused function in CharacterTest

GitOrigin-RevId: 0bf230d4220660af8b2667506f8905df2f716bdf
diff --git a/unittests/Optimizer/Builder/CharacterTest.cpp b/unittests/Optimizer/Builder/CharacterTest.cpp
index 64daf94..7cf15b0 100644
--- a/unittests/Optimizer/Builder/CharacterTest.cpp
+++ b/unittests/Optimizer/Builder/CharacterTest.cpp
@@ -41,14 +41,6 @@
   std::unique_ptr<fir::FirOpBuilder> firBuilder;
 };
 
-static void checkIntegerConstant(mlir::Value value, mlir::Type ty, int64_t v) {
-  EXPECT_TRUE(mlir::isa<ConstantOp>(value.getDefiningOp()));
-  auto cstOp = dyn_cast<ConstantOp>(value.getDefiningOp());
-  EXPECT_EQ(ty, cstOp.getType());
-  auto valueAttr = cstOp.getValue().dyn_cast_or_null<IntegerAttr>();
-  EXPECT_EQ(v, valueAttr.getInt());
-}
-
 TEST_F(CharacterTest, smallUtilityFunctions) {
   auto builder = getBuilder();
   auto loc = builder.getUnknownLoc();