[Float2Int] Add pre-commit tests. NFC.

Author: dtcxzyw

llvm/test/Transforms/Float2Int/pr167627.ll

@@ -0,0 +1,16 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
+; RUN: opt -S -passes=float2int < %s | FileCheck %s
+
+; Make sure that we don't demote constant floating-point values when
+; it cannot be represented by target integer type.
+
+define i1 @pr167627() {
+; CHECK-LABEL: define i1 @pr167627() {
+; CHECK-NEXT:  [[ENTRY:.*:]]
+; CHECK-NEXT:    ret i1 false
+;
+entry:
+  %fadd = fadd float 0xC5AAD8ABE0000000, 0xC57E819700000000
+  %cmp = fcmp one float %fadd, 0.000000e+00
+  ret i1 %cmp
+}