gn format: Make defines, deps, and sources lists always multline

tools/gn/format_test_data/042.golden

Index: tools/gn/format_test_data/042.golden
diff --git a/tools/gn/format_test_data/042.golden b/tools/gn/format_test_data/042.golden
new file mode 100644
index 0000000000000000000000000000000000000000..983cec2bc3936f98dc5de4236d80cc42009f65f5
--- /dev/null
+++ b/tools/gn/format_test_data/042.golden
@@ -0,0 +1,101 @@
+# Test zero, one, and multiple element for specifically named LHSs.
+if (true) {
+  cflags = []
+  cflags_c = []
+  cflags_cc = []
+  data = []
+  datadeps = []
+  defines = []
+  deps = []
+  include_dirs = []
+  inputs = []
+  ldflags = []
+  public_deps = []
+  sources = []
+} else if (true) {
+  cflags = [ "x" ]
+  cflags_c = [ "x" ]
+  cflags_cc = [ "x" ]
+  data = [
+    "x",
+  ]
+  datadeps = [
+    "x",
+  ]
+  defines = [ "x" ]
+  deps = [
+    "x",
+  ]
+  include_dirs = [ "x" ]
+  inputs = [
+    "x",
+  ]
+  ldflags = [ "x" ]
+  public_deps = [
+    "x",
+  ]
+  sources = [
+    "x",
+  ]
+} else {
+  cflags = [
+    "x",
+    "y",
+    "z",
+  ]
+  cflags_c = [
+    "x",
+    "y",
+    "z",
+  ]
+  cflags_cc = [
+    "x",
+    "y",
+    "z",
+  ]
+  data = [
+    "x",
+    "y",
+    "z",
+  ]
+  datadeps = [
+    "x",
+    "y",
+    "z",
+  ]
+  defines = [
+    "x",
+    "y",
+    "z",
+  ]
+  deps = [
+    "x",
+    "y",
+    "z",
+  ]
+  include_dirs = [
+    "x",
+    "y",
+    "z",
+  ]
+  inputs = [
+    "x",
+    "y",
+    "z",
+  ]
+  ldflags = [
+    "x",
+    "y",
+    "z",
+  ]
+  public_deps = [
+    "x",
+    "y",
+    "z",
+  ]
+  sources = [
+    "x",
+    "y",
+    "z",
+  ]
+}