[compiler] Add HIRFunction.returns: Place

[josephsavona]

Stack from ghstack (oldest at bottom):

• [compiler][newinference] Impure/Render effects #33488
• [compiler][newinference] Fixes, update remaining snapshots #33477
• [compiler][newinference] Update fixtures #33471
• [compiler][newinference] Improve hoisted functions, validation of mutate-after-render #33470
• [compiler] fixes for effects capturing context vars, hoisted functions #33469
• [compiler][newinference] Explicitly model StoreContext variables as mutable boxes #33465
• [compiler][newinference] Error handling and related fixes #33458
• [compiler][newinference] ensure fixpoint converges for loops w backedges #33449
• [compiler][newinference] Fix for phi types, extracting primitives from objects #33440
• [compiler][newinference] Fixes for transitive function capturing, mutation via property loads #33430
• [compiler] Effects for Return/MaybeThrow terminals #33429
• [compiler] Post/Pre-FixUpdate, try/catch, ConditionallyMutateIterator support #33427
• [compiler] Further improve new range inference #33411
• [compiler] InferMutationAliasingRanges precisely models which values mutate when #33401
• [compiler] Fix mutable ranges for StoreContext #33386
• [compiler] Distinguish Alias/Assign effects #33385
• [compiler] Effect inference across signatures and user-provided callbacks #33384
• [compiler] Receiver is mutate? for functions wo signatures #33380
• [compiler] Handle legacy mutableIfOperandsMutable signatures #33379
• [compiler] Prep for making new/call/etc use Apply effects #33378
• [compiler] Bailout on mutations of frozen/global values #33377
• [compiler] comments and todos #33376
• [compiler] Translate legacy FunctionSignature into new AliasingEffects #33371
• [compiler] First example of an aliasing signature (array push) #33370
• [compiler] Delay mutation of function expr context variables until function is called #33369
• [compiler] Add ImmutableCapture effect, CreateFrom no longer needs Capture #33367
• [compiler] Improve inference of function expression mutation/aliasing effects #33365
• [compiler] Alternate pipeline for new mutability model #33364
• -> [compiler] Add HIRFunction.returns: Place #33363
• [compiler] Foundation of new mutability and aliasing (alternate take) #33346
• [compiler] Add Instruction.effects property #33350
• [compiler] Repro for imprecise memo due to closure capturing changes #33180
• [compiler] avoid empty switch case bodies #33179
• [compiler] allow local fixtures to be excluded from git w "nocommit" prefix #33178
• [compiler] Fix for PropertyStore object effect #33164
• [compiler] Fixture tests for PropertyStore effects #33163
• [compiler] Move co-mutation range extension to InferMutableRanges #33157
• [compiler] Infer alias effects for function expressions #33151
• [compiler] Correctly infer context mutation places as outer (context) places #33114
• [compiler] Repro for false positive ValidateNoFreezingKnownMutableFunctions #33113