backport copy elision changes

This commit contains everything from the copy-elision-2
branch that does not have to do with copy elision directly,
but is generally useful for master branch.

 * All const values know their parents, when applicable, not
   just structs and unions.
 * Null pointers in const values are represented explicitly,
   rather than as a HardCodedAddr value of 0.
 * Rename "maybe" to "optional" in various code locations.
 * Separate DeclVarSrc and DeclVarGen
 * Separate PtrCastSrc and PtrCastGen
 * Separate CmpxchgSrc and CmpxchgGen
 * Represent optional error set as an integer, using the 0 value.
   In a const value, it uses nullptr.
 * Introduce type_has_one_possible_value and use it where applicable.
 * Fix debug builds not setting memory to 0xaa when storing
   undefined.
 * Separate the type of a variable from the const value of a variable.
 * Use copy_const_val where appropriate.
 * Rearrange structs to pack data more efficiently.
 * Move test/cases/* to test/behavior/*
 * Use `std.debug.assertOrPanic` in behavior tests instead of
   `std.debug.assert`.
 * Fix outdated slice syntax in docs.

1 files changed, 0 insertions, 59 deletions

diff --git a/test/cases/syntax.zig b/test/cases/syntax.zig
deleted file mode 100644
index 0c8c3c5ed3..0000000000
--- a/test/cases/syntax.zig
+++ /dev/null
@@ -1,59 +0,0 @@
-// Test trailing comma syntax
-// zig fmt: off
-
-const struct_trailing_comma = struct { x: i32, y: i32, };
-const struct_no_comma = struct { x: i32, y: i32 };
-const struct_fn_no_comma = struct { fn m() void {} y: i32 };
-
-const enum_no_comma = enum { A, B };
-
-fn container_init() void {
-    const S = struct { x: i32, y: i32 };
-    _ = S { .x = 1, .y = 2 };
-    _ = S { .x = 1, .y = 2, };
-}
-
-fn type_expr_return1() if (true) A {}
-fn type_expr_return2() for (true) |_| A {}
-fn type_expr_return3() while (true) A {}
-fn type_expr_return4() comptime A {}
-
-fn switch_cases(x: i32) void {
-    switch (x) {
-        1,2,3 => {},
-        4,5, => {},
-        6...8, => {},
-        else => {},
-    }
-}
-
-fn switch_prongs(x: i32) void {
-    switch (x) {
-        0 => {},
-        else => {},
-    }
-    switch (x) {
-        0 => {},
-        else => {}
-    }
-}
-
-const fn_no_comma = fn(i32, i32)void;
-const fn_trailing_comma = fn(i32, i32,)void;
-
-fn fn_calls() void {
-    fn add(x: i32, y: i32,) i32 { x + y };
-    _ = add(1, 2);
-    _ = add(1, 2,);
-}
-
-fn asm_lists() void {
-    if (false) { // Build AST but don't analyze
-        asm ("not real assembly"
-            :[a] "x" (x),);
-        asm ("not real assembly"
-            :[a] "x" (->i32),:[a] "x" (1),);
-        asm ("still not real assembly"
-            :::"a","b",);
-    }
-}