closes#346closes#630
regression: translate-c can no longer translate switch statements.
after #629 we can ressurect and modify the code to utilize arbitrarily
returning from blocks.
* @enumTagName renamed to @tagName and it works on enums and
union-enums
* Remove the EnumTag type. Now there is only enum and union,
and the tag type of a union is always an enum.
* unions support specifying the tag enum type, and they support
inferring an enum tag type.
* Enums no longer support field types but they do support
setting the tag values. Likewise union-enums when inferring
an enum tag type support setting the tag values.
* It is now an error for enums and unions to have 0 fields.
* switch statements support union-enums
closes#618
* remove `@setGlobalAlign`
* add align keyword for setting alignment on functions and
variables.
* loads and stores use alignment from pointer
* memcpy, memset use alignment from pointer
* add syntax for pointer alignment
* slices can have volatile
* add u2, i2 primitives
* ignore preferred align and use abi align everywhere
* back to only having alignOf builtin.
preferredAlignOf is too tricky to be useful.
See #432. Partial revert of
e726925e802eddab53cbfd9aacbc5eefe95c356f.
See #37
Before:
* << is left shift, not allowed to shift 1 bits out
* <<% is left shift, allowed to shift 1 bits out
* >> is right shift, allowed to shift 1 bits out
After:
* << is left shift, allowed to shift 1 bits out
* >> is right shift, allowed to shift 1 bits out
* @shlExact is left shift, not allowed to shift 1 bits out
* @shrExact is right shift, not allowed to shift 1 bits out
Closes#413
Old:
```
while (condition; expression) {}
```
New:
```
while (condition) : (expression) {}
```
This is in preparation to allow nullable and
error union types as the condition. See #357
implicit semicolon rules apply recursively to the "else" clause of if and try
if (a) {} else {} // implicit semicolon
if (a) {} else if (a) {} // implicit semicolon
if (a) {} else while (a) {} // implicit semicolon
closes#292
* if, try, while, for, comptime, defer are "greedy" with {} blocks,
meaning if their bodies are blocks, then no suffix operator is allowed
after the block. The {} block gets "built into" the containing statement,
like the body of a switch statement.
* the Expression syntactic element is no longer "greedy" with {} blocks,
meaning it's possible to have suffix operators after {} blocks without
needing the {} block to be an rhs operand first.
* Don't insert void statements all over the place. {} now stays as
{} instead of {{}}, and {;} becomes {} instead of {{};{}}.
* Ensure final statement is always the return value statement, or
the block is empty. This means {label:} becomes {label:{}}.
it outputs a number that is unique to each instance of the asm
statement in the entire compilation.
useful when creating local labels and referring to them multiple
times in a single template that generates multiple
assembler instructions
