CLI: add 'run' command to the repl

std.ArrayHashMap: ensureUnusedCapacity and ensureTotalCapacity

stage2: fix contents hash computation

stage2: mapping old to new ZIR recursively

std.ArrayList: add clearRetainingCapacity and clearAndFree

stage2: add `zig changelist` debug command

std: fix compile errors found by stage2

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

Sema: restore the extern lib name functionality

stage2: test coverage for inline asm return type not type

Sema: implement error sets

stage2: fix "other symbol here" error note

stage2: fix structs and enums setting wrong owner_decl

build.zig: add -Dmem-leak-frames option

Sema: implement ExportOptions support in `@export`

ZIR: typeof uses the un_node field not un_tok

Sema: implement struct_decl instruction

ZIR: implement debug text printing for struct_init and friends

stage2: hook up semantic analysis of struct fields

stage2: make struct field analysis lazy

AstGen: fix outdated doc comment

AstGen: decouple from Module/Compilation

stage2: fix error reporting not loading AST

stage2: test decls encode that they are tests in ZIR

Sema: fix struct decl decoding ZIR incorrectly

stage2: dbg_stmt ZIR instructions have line/col

std.GeneralPurposeAllocator: print leaked memory addresses

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

stage2: implement function body analysis

stage2: introduce new ZIR instruction: arg

Sema: implement function declarations

start.zig: unconditionally import the root source file

stage2: un-tangle memory management of Decl and Namespace

stage2: fix File incorrectly freeing its Namespace

stage2: properly free Decl name

std: fix compile errors found by stage2 AstGen

AstGen: represent global variables directly

AstGen: implement extern variables

AstGen: implement function prototypes with alignment exprs

AstGen: fix comptime compile error source location

Sema: rename TZIR to AIR

Sema: skip analysis of empty enum blocks

AstGen: implement anytype struct fields

AstGen: implement comptime struct fields

std.enums: remove stuff for enums with field aliases

move behavior tests from test/stage1/ to test/

update behavior tests with respect to new builtin pkg

tests: prepare behavior tests for stage2

stage2: fix scanDecls not advancing the field bits

std: remove redundant comptime keyword

stage2: implement semantic analysis for functions and global vars

stage2: prepare for mainining Decl references to ZIR indexes

stage2: semaDecl properly analyzes the decl block

Sema: do not analyze test decls when not in test mode

stage2: implement #8364

std: remove redundant `comptime const`

AstGen: hook up hex float parsing to float literals

AstGen: function prototypes can have alignment

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

AstGen: fix function src hash not including body

link: fix compile error from previous commit

stage2: rewire the frontend driver to whole-file-zir

AstGen: improved handling of declarations

AstGen: implement opaque decls

stage2: pre-open ZIR cache dir handles

stage2: implement caching for ZIR code

AstGen: implement `@Vector`

stage2: move overflow builtin ZIR instructions to Extended

AstGen: parser ensures all suspend have blocks

AstGen: implement await and resume

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

stage2: better error reporting for LazySrcLoc.entire_file

AstGen: support struct init with ref result location

stage2: remove call_none and call_none_chkused ZIR

stage2: remove dead ZIR instructions

AstGen: emit nosuspend function calls

AstGen: implement nosuspend expressions

AstGen: implement suspend blocks

stage2: implement `anyframe`, `anyframe->T` and fix assembly

AstGen: compile error for unable to infer array size

std: remove `comptime const`

AstGen: implement integers bigger than u64

stage2: write out builtin.zig before spawning AstGen tasks

ZIR: fix text printing of field_ptr_type

stage2: fix builtin.zig for `zig test`

std: fix potential bug in parseInt

std: fix compile errors caught by stage2 AstGen

delete packed enums from the language

AstGen: implement align and linksection on globals

std: fix compile errors caught by stage2 AstGen

AstGen: implement `@extern` builtin

AstGen: fix `@export`

AstGen: implement function prototypes

AstGen: implement alignment on locals

AstGen: implement comptime locals

AstGen: fix switch result location elision

AstGen: implement `@bitCast` for other result location types

AstGen: fix `@floatCast` having wrong arity

AstGen: slightly better eager-allocating heuristic

AstGen: implement union decls