Sema: implement array coercion

test/behavior/array.zig

@@ -164,3 +164,53 @@ test "read/write through global variable array of struct fields initialized via
     };
     try S.doTheTest();
 }
+
+test "single-item pointer to array indexing and slicing" {
+    try testSingleItemPtrArrayIndexSlice();
+    comptime try testSingleItemPtrArrayIndexSlice();
+}
+
+fn testSingleItemPtrArrayIndexSlice() !void {
+    {
+        var array: [4]u8 = "aaaa".*;
+        doSomeMangling(&array);
+        try expect(mem.eql(u8, "azya", &array));
+    }
+    {
+        var array = "aaaa".*;
+        doSomeMangling(&array);
+        try expect(mem.eql(u8, "azya", &array));
+    }
+}
+
+fn doSomeMangling(array: *[4]u8) void {
+    array[1] = 'z';
+    array[2..3][0] = 'y';
+}
+
+test "implicit cast zero sized array ptr to slice" {
+    {
+        var b = "".*;
+        const c: []const u8 = &b;
+        try expect(c.len == 0);
+    }
+    {
+        var b: [0]u8 = "".*;
+        const c: []const u8 = &b;
+        try expect(c.len == 0);
+    }
+}
+
+test "anonymous list literal syntax" {
+    const S = struct {
+        fn doTheTest() !void {
+            var array: [4]u8 = .{ 1, 2, 3, 4 };
+            try expect(array[0] == 1);
+            try expect(array[1] == 2);
+            try expect(array[2] == 3);
+            try expect(array[3] == 4);
+        }
+    };
+    try S.doTheTest();
+    comptime try S.doTheTest();
+}