first pass at zig build system

 * `zig build --export [obj|lib|exe]` changed to `zig build_obj`,
   `zig build_lib` and `zig build_exe` respectively.
 * `--name` parameter is optional when it can be inferred from the
   root source filename. closes #207
 * `zig build` now looks for `build.zig` which interacts with
   `std.build.Builder` to describe the targets, and then the zig
   build system prints TODO: build these targets. See #204
 * add `@bitcast` which is mainly used for pointer reinterpret
   casting and make explicit casting not do pointer reinterpretation.
   Closes #290
 * fix debug info for byval parameters
 * sort command line help options
 * `std.debug.panic` supports format string printing
 * add `std.mem.IncrementingAllocator`
 * fix const ptr to a variable with data changing at runtime.
   closes #289

1 files changed, 15 insertions, 0 deletions

diff --git a/test/cases/eval.zig b/test/cases/eval.zig
index b1d10ca8bf..0d52985329 100644
--- a/test/cases/eval.zig
+++ b/test/cases/eval.zig
@@ -284,3 +284,18 @@ fn testCompTimeUIntComparisons(x: u32) {
         @compileError("this condition should be comptime known");
     }
 }
+
+
+
+test "const ptr to variable data changes at runtime" {
+    assert(foo_ref.name[0] == 'a');
+    foo_ref.name = "b";
+    assert(foo_ref.name[0] == 'b');
+}
+
+const Foo = struct {
+    name: []const u8,
+};
+
+var foo_contents = Foo { .name = "a", };
+const foo_ref = &foo_contents;