Stdx: Export backported HashMap

src/lsm/table_mutable.zig

@@ -22,8 +22,7 @@ pub fn TableMutableType(comptime Table: type, comptime tree_name: [:0]const u8)
         const TableMutable = @This();
 
         const load_factor = 50;
-        /// TODO(Zig): Import from std. See https://github.com/ziglang/zig/pull/15989.
-        const Values = @import("../hash_map.zig").HashMapUnmanaged(
+        const Values = stdx.HashMapUnmanaged(
             Value,
             void,
             Table.HashMapContextValue,

src/stdx.zig

@@ -4,6 +4,12 @@ const std = @import("std");
 const builtin = @import("builtin");
 const assert = std.debug.assert;
 
+/// TODO(Zig): Remove these and import directly from std.
+/// See https://github.com/ziglang/zig/pull/15989.
+/// This backported HashMap is only needed when fetchRemove() will be used.
+pub const HashMapUnmanaged = @import("./hash_map.zig").HashMapUnmanaged;
+pub const AutoHashMapUnmanaged = @import("./hash_map.zig").AutoHashMapUnmanaged;
+
 pub inline fn div_ceil(numerator: anytype, denominator: anytype) @TypeOf(numerator, denominator) {
     comptime {
         switch (@typeInfo(@TypeOf(numerator))) {

src/vsr/superblock_client_sessions.zig

@@ -38,8 +38,7 @@ pub const ClientSessions = struct {
     };
 
     /// Values are indexes into `entries`.
-    /// TODO(Zig): Import from std. See https://github.com/ziglang/zig/pull/15989.
-    const EntriesByClient = @import("../hash_map.zig").AutoHashMapUnmanaged(u128, usize);
+    const EntriesByClient = stdx.AutoHashMapUnmanaged(u128, usize);
 
     /// Free entries are zeroed, both in `entries` and on-disk.
     entries: []Entry,