GH-47234: [C++][Python] Add test for fill_null regression on Windows (#47249)

### Rationale for this change

Add regression test for an issue that surfaced on specific MSVC versions, presumably due to a compiler bug.

Possible upstream tickets are https://developercommunity.visualstudio.com/t/Code-optimization-bug-SIMD-std::transf/10912292 and https://developercommunity.visualstudio.com/t/SIMD-Code-optimization-bug/10945478.

### What changes are included in this PR?

Additional tests to catch any further occurrence of this specific problem.

### Are these changes tested?

Obviously yes.

### Are there any user-facing changes?

No.

* GitHub Issue: #47234

Lead-authored-by: Antoine Pitrou <[email protected]>
Co-authored-by: Rok Mihevc <[email protected]>
Co-authored-by: Antoine Pitrou <[email protected]>
Signed-off-by: Antoine Pitrou <[email protected]>

Author: rok

cpp/src/arrow/compute/kernels/scalar_if_else_test.cc

@@ -3144,6 +3144,14 @@ TEST(TestCoalesce, Boolean) {
               ArrayFromJSON(type, "[true, true, false, true]"));
   CheckScalar("coalesce", {scalar1, values1},
               ArrayFromJSON(type, "[false, false, false, false]"));
+
+  // Regression test for GH-47234, which was failing due to a MSVC compiler bug
+  // (possibly https://developercommunity.visualstudio.com/t/10912292
+  // or https://developercommunity.visualstudio.com/t/10945478).
+  auto values_with_null = ArrayFromJSON(type, "[true, false, false, false, false, null]");
+  auto expected = ArrayFromJSON(type, "[true, false, false, false, false, true]");
+  auto scalar2 = ScalarFromJSON(type, "true");
+  CheckScalar("coalesce", {values_with_null, scalar2}, expected);
 }
 
 TEST(TestCoalesce, DayTimeInterval) {

python/pyarrow/tests/test_compute.py

@@ -1952,6 +1952,28 @@ def test_fill_null_chunked_array(arrow_type):
     assert result.equals(expected)
 
 
+def test_fill_null_windows_regression():
+    # Regression test for GH-47234, which was failing due to a MSVC compiler bug
+    # (possibly https://developercommunity.visualstudio.com/t/10912292
+    # or https://developercommunity.visualstudio.com/t/10945478)
+    arr = pa.array([True, False, False, False, False, None])
+    s = pa.scalar(True, type=pa.bool_())
+
+    result = pa.compute.call_function("coalesce", [arr, s])
+    result.validate(full=True)
+    expected = pa.array([True, False, False, False, False, True])
+    assert result.equals(expected)
+
+    for ty in [pa.int8(), pa.int16(), pa.int32(), pa.int64()]:
+        arr = pa.array([1, 2, 3, 4, 5, None], type=ty)
+        s = pa.scalar(42, type=ty)
+
+        result = pa.compute.call_function("coalesce", [arr, s])
+        result.validate(full=True)
+        expected = pa.array([1, 2, 3, 4, 5, 42], type=ty)
+        assert result.equals(expected)
+
+
 def test_logical():
     a = pa.array([True, False, False, None])
     b = pa.array([True, True, False, True])