Merge remote-tracking branch 'origin/master' into stage2-whole-file-astgen

Conflicts:
 * lib/std/os/linux.zig
 * lib/std/os/windows/bits.zig
 * src/Module.zig
 * src/Sema.zig
 * test/stage2/test.zig

Mainly I wanted Jakub's new macOS code for respecting stack size, since
we now depend on it for debug builds able to pass one of the test cases
for recursive comptime function calls with `@setEvalBranchQuota`.

The conflicts were all trivial.

lib/std/array_hash_map.zig

@@ -18,11 +18,11 @@ const builtin = std.builtin;
 const hash_map = @This();
 
 pub fn AutoArrayHashMap(comptime K: type, comptime V: type) type {
-    return ArrayHashMap(K, V, getAutoHashFn(K), getAutoEqlFn(K), autoEqlIsCheap(K));
+    return ArrayHashMap(K, V, getAutoHashFn(K), getAutoEqlFn(K), !autoEqlIsCheap(K));
 }
 
 pub fn AutoArrayHashMapUnmanaged(comptime K: type, comptime V: type) type {
-    return ArrayHashMapUnmanaged(K, V, getAutoHashFn(K), getAutoEqlFn(K), autoEqlIsCheap(K));
+    return ArrayHashMapUnmanaged(K, V, getAutoHashFn(K), getAutoEqlFn(K), !autoEqlIsCheap(K));
 }
 
 /// Builtin hashmap for strings as keys.
@@ -1318,7 +1318,7 @@ test "reIndex" {
         try al.append(std.testing.allocator, .{
             .key = i,
             .value = i * 10,
-            .hash = hash(i),
+            .hash = {},
         });
     }
 
@@ -1345,7 +1345,7 @@ test "fromOwnedArrayList" {
         try al.append(std.testing.allocator, .{
             .key = i,
             .value = i * 10,
-            .hash = hash(i),
+            .hash = {},
         });
     }
 
@@ -1362,6 +1362,18 @@ test "fromOwnedArrayList" {
     }
 }
 
+test "auto store_hash" {
+    const HasCheapEql = AutoArrayHashMap(i32, i32);
+    const HasExpensiveEql = AutoArrayHashMap([32]i32, i32);
+    try testing.expect(meta.fieldInfo(HasCheapEql.Entry, .hash).field_type == void);
+    try testing.expect(meta.fieldInfo(HasExpensiveEql.Entry, .hash).field_type != void);
+
+    const HasCheapEqlUn = AutoArrayHashMapUnmanaged(i32, i32);
+    const HasExpensiveEqlUn = AutoArrayHashMapUnmanaged([32]i32, i32);
+    try testing.expect(meta.fieldInfo(HasCheapEqlUn.Entry, .hash).field_type == void);
+    try testing.expect(meta.fieldInfo(HasExpensiveEqlUn.Entry, .hash).field_type != void);
+}
+
 pub fn getHashPtrAddrFn(comptime K: type) (fn (K) u32) {
     return struct {
         fn hash(key: K) u32 {