test: Set emit_bin=false for all nvptx tests.

error: thread 165232 panic: TODO: rewrite the NvPtx.flushModule function
/home/alexrp/Source/ziglang/zig/src/link/NvPtx.zig:123:5: 0x1ed99ce in flushModule (zig)
    @panic("TODO: rewrite the NvPtx.flushModule function");
    ^
/home/alexrp/Source/ziglang/zig/src/link/NvPtx.zig:110:28: 0x1c2e7e6 in flush (zig)
    return self.flushModule(arena, tid, prog_node);
                           ^
/home/alexrp/Source/ziglang/zig/src/link.zig:874:77: 0x1a55bd3 in flush (zig)
                return @as(*tag.Type(), @fieldParentPtr("base", base)).flush(arena, tid, prog_node);
                                                                            ^
/home/alexrp/Source/ziglang/zig/src/Compilation.zig:2411:17: 0x1a553f9 in flush (zig)
        lf.flush(arena, tid, prog_node) catch |err| switch (err) {
                ^
/home/alexrp/Source/ziglang/zig/src/Compilation.zig:2348:22: 0x1a595ba in update (zig)
            try flush(comp, arena, .{
                     ^
/home/alexrp/Source/ziglang/zig/src/main.zig:4114:32: 0x1ae392b in serve (zig)
                try comp.update(main_progress_node);
                               ^
/home/alexrp/Source/ziglang/zig/src/main.zig:3555:22: 0x1b05322 in buildOutputType (zig)
            try serve(
                     ^
/home/alexrp/Source/ziglang/zig/src/main.zig:265:31: 0x195faca in mainArgs (zig)
        return buildOutputType(gpa, arena, args, .{ .build = .Obj });
                              ^
/home/alexrp/Source/ziglang/zig/src/main.zig:200:20: 0x195c995 in main (zig)
    return mainArgs(gpa, arena, args);
                   ^
/home/alexrp/Source/ziglang/zig/lib/std/start.zig:617:37: 0x195c49e in main (zig)
            const result = root.main() catch |err| {
                                    ^

test/nvptx.zig

@@ -95,6 +95,7 @@ fn addPtx(ctx: *Cases, target: std.Build.ResolvedTarget, name: []const u8) *Case
         .output_mode = .Obj,
         .deps = std.ArrayList(Cases.DepModule).init(ctx.cases.allocator),
         .link_libc = false,
+        .emit_bin = false,
         .backend = .llvm,
         // Bug in Debug mode
         .optimize_mode = .ReleaseSafe,