[IRBuilder] fix CreateMaxNum to actually produce maxnum (PR36454)

The bug was introduced here:
https://reviews.llvm.org/rL296409
...but the patch doesn't use maxnum and nothing else in 
trunk has tried since then, so the bug went unnoticed.

llvm-svn: 325607

llvm/include/llvm/IR/IRBuilder.h

@@ -676,7 +676,7 @@ public:
 
   /// Create call to the maxnum intrinsic.
   CallInst *CreateMaxNum(Value *LHS, Value *RHS, const Twine &Name = "") {
-    return CreateBinaryIntrinsic(Intrinsic::minnum, LHS, RHS, Name);
+    return CreateBinaryIntrinsic(Intrinsic::maxnum, LHS, RHS, Name);
   }
 
 private:

llvm/unittests/IR/IRBuilderTest.cpp

@@ -48,6 +48,23 @@ protected:
   GlobalVariable *GV;
 };
 
+TEST_F(IRBuilderTest, Intrinsics) {
+  IRBuilder<> Builder(BB);
+  Value *V;
+  CallInst *Call;
+  IntrinsicInst *II;
+
+  V = Builder.CreateLoad(GV);
+
+  Call = Builder.CreateMinNum(V, V);
+  II = cast<IntrinsicInst>(Call);
+  EXPECT_EQ(II->getIntrinsicID(), Intrinsic::minnum);
+
+  Call = Builder.CreateMaxNum(V, V);
+  II = cast<IntrinsicInst>(Call);
+  EXPECT_EQ(II->getIntrinsicID(), Intrinsic::maxnum);
+}
+
 TEST_F(IRBuilderTest, Lifetime) {
   IRBuilder<> Builder(BB);
   AllocaInst *Var1 = Builder.CreateAlloca(Builder.getInt8Ty());