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 * Fix outdated slice syntax in docs.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, 26 deletions

diff --git a/test/cases/new_stack_call.zig b/test/cases/new_stack_call.zig
deleted file mode 100644
index 5912550d54..0000000000
--- a/test/cases/new_stack_call.zig
+++ /dev/null
@@ -1,26 +0,0 @@
-const std = @import("std");
-const assert = std.debug.assert;
-
-var new_stack_bytes: [1024]u8 = undefined;
-
-test "calling a function with a new stack" {
-    const arg = 1234;
-
-    const a = @newStackCall(new_stack_bytes[0..512], targetFunction, arg);
-    const b = @newStackCall(new_stack_bytes[512..], targetFunction, arg);
-    _ = targetFunction(arg);
-
-    assert(arg == 1234);
-    assert(a < b);
-}
-
-fn targetFunction(x: i32) usize {
-    assert(x == 1234);
-
-    var local_variable: i32 = 42;
-    const ptr = &local_variable;
-    ptr.* += 1;
-
-    assert(local_variable == 43);
-    return @ptrToInt(ptr);
-}