clang-format: With ColumnLimit=0, keep short array literals on a line.

Before:
    NSArray* a = [[NSArray alloc] initWithArray:@[
                                                   @"a"
                                                ]
                                      copyItems:YES];

After:
    NSArray* a = [[NSArray alloc] initWithArray:@[ @"a" ]
                                      copyItems:YES];

This fixed llvm.org/PR19080.

llvm-svn: 206161
diff --git a/clang/unittests/Format/FormatTest.cpp b/clang/unittests/Format/FormatTest.cpp
index 0dc0659..7bae21b 100644
--- a/clang/unittests/Format/FormatTest.cpp
+++ b/clang/unittests/Format/FormatTest.cpp
@@ -8148,6 +8148,20 @@
             format("#define aNumber \\\n"
                    " 10",
                    Style));
+
+  // Keep empty and one-element array literals on a single line.
+  verifyFormat("NSArray* a = [[NSArray alloc] initWithArray:@[]\n"
+               "                                  copyItems:YES];",
+               Style);
+  verifyFormat("NSArray* a = [[NSArray alloc] initWithArray:@[ @\"a\" ]\n"
+               "                                  copyItems:YES];",
+               Style);
+  verifyFormat("NSArray* a = [[NSArray alloc] initWithArray:@[\n"
+               "                                               @\"a\",\n"
+               "                                               @\"a\"\n"
+               "                                            ]\n"
+               "                                  copyItems:YES];",
+               Style);
 }
 
 TEST_F(FormatTest, FormatsLambdas) {