Rollup merge of #122197 - lcnr:proof-tree-braces, r=BoxyUwU
inspect formatter: add braces
This makes it easier to hide subtrees when looking through proof trees. Looking at the proof tree for `usize: Clone`:
nightly:
```
ROOT GOAL: Goal { predicate: Binder { value: TraitPredicate(<usize as std::clone::Clone>, polarity:Positive), bound_vars: [] }, param_env: ParamEnv { caller_bounds: [], reveal: UserFacing } }
GOAL: Canonical { value: QueryInput { goal: Goal { predicate: Binder { value: TraitPredicate(<usize as std::clone::Clone>, polarity:Positive), bound_vars: [] }, param_env: ParamEnv { caller_bounds: [], reveal: UserFacing } }, anchor: Bind(DefId(0:5 ~ main[8e4b]::main)), predefined_opaques_in_body: PredefinedOpaques(PredefinedOpaquesData { opaque_types: [] }) }, max_universe: U0, variables: [] }
REVISION 0
INSTANTIATED: QueryInput { goal: Goal { predicate: Binder { value: TraitPredicate(<usize as std::clone::Clone>, polarity:Positive), bound_vars: [] }, param_env: ParamEnv { caller_bounds: [], reveal: UserFacing } }, anchor: Bind(DefId(0:5 ~ main[8e4b]::main)), predefined_opaques_in_body: PredefinedOpaques(PredefinedOpaquesData { opaque_types: [] }) }
ROOT RESULT: Ok(Canonical { value: Response { certainty: Yes, var_values: CanonicalVarValues { var_values: [] }, external_constraints: ExternalConstraints(ExternalConstraintsData { region_constraints: QueryRegionConstraints { outlives: [], member_constraints: [] }, opaque_types: [] }) }, max_universe: U0, variables: [] })
CANDIDATE Impl(DefId(2:30665 ~ core[a9f5]::clone::impls::{impl#5})): Ok(Canonical { value: Response { certainty: Yes, var_values: CanonicalVarValues { var_values: [] }, external_constraints: ExternalConstraints(ExternalConstraintsData { region_constraints: QueryRegionConstraints { outlives: [], member_constraints: [] }, opaque_types: [] }) }, max_universe: U0, variables: [] })
TRY_EVALUATE_ADDED_GOALS: Ok(Yes)
ITERATION 0
CANDIDATE constituent tys: Err(NoSolution)
NORMALIZING SELF TY FOR ASSEMBLY:
NORMALIZING SELF TY FOR ASSEMBLY:
RESULT: Ok(Canonical { value: Response { certainty: Yes, var_values: CanonicalVarValues { var_values: [] }, external_constraints: ExternalConstraints(ExternalConstraintsData { region_constraints: QueryRegionConstraints { outlives: [], member_constraints: [] }, opaque_types: [] }) }, max_universe: U0, variables: [] })
```
with this PR:
```
ROOT GOAL: Goal { predicate: Binder { value: TraitPredicate(<usize as std::clone::Clone>, polarity:Positive), bound_vars: [] }, param_env: ParamEnv { caller_bounds: [], reveal: UserFacing } } {
GOAL: Canonical { value: QueryInput { goal: Goal { predicate: Binder { value: TraitPredicate(<usize as std::clone::Clone>, polarity:Positive), bound_vars: [] }, param_env: ParamEnv { caller_bounds: [], reveal: UserFacing } }, anchor: Bind(DefId(0:5 ~ main[4f74]::main)), predefined_opaques_in_body: PredefinedOpaques(PredefinedOpaquesData { opaque_types: [] }) }, max_universe: U0, variables: [] }
REVISION 0: {
INSTANTIATED: QueryInput { goal: Goal { predicate: Binder { value: TraitPredicate(<usize as std::clone::Clone>, polarity:Positive), bound_vars: [] }, param_env: ParamEnv { caller_bounds: [], reveal: UserFacing } }, anchor: Bind(DefId(0:5 ~ main[4f74]::main)), predefined_opaques_in_body: PredefinedOpaques(PredefinedOpaquesData { opaque_types: [] }) }
ROOT RESULT: Ok(Canonical { value: Response { certainty: Yes, var_values: CanonicalVarValues { var_values: [] }, external_constraints: ExternalConstraints(ExternalConstraintsData { region_constraints: QueryRegionConstraints { outlives: [], member_constraints: [] }, opaque_types: [] }) }, max_universe: U0, variables: [] }) {
CANDIDATE Impl(DefId(2:30468 ~ core[d1d7]::clone::impls::{impl#5})): Ok(Canonical { value: Response { certainty: Yes, var_values: CanonicalVarValues { var_values: [] }, external_constraints: ExternalConstraints(ExternalConstraintsData { region_constraints: QueryRegionConstraints { outlives: [], member_constraints: [] }, opaque_types: [] }) }, max_universe: U0, variables: [] }) {
TRY_EVALUATE_ADDED_GOALS: Ok(Yes)
ITERATION 0 {}
}
CANDIDATE constituent tys: Err(NoSolution) {}
NORMALIZING SELF TY FOR ASSEMBLY: {}
NORMALIZING SELF TY FOR ASSEMBLY: {}
}
}
RESULT: Ok(Canonical { value: Response { certainty: Yes, var_values: CanonicalVarValues { var_values: [] }, external_constraints: ExternalConstraints(ExternalConstraintsData { region_constraints: QueryRegionConstraints { outlives: [], member_constraints: [] }, opaque_types: [] }) }, max_universe: U0, variables: [] })
}
```
r? `@BoxyUwU`
bf939fcb99