This PR adds new predicates to `Declaration` and `Type` to get a fully-qualified canonical name for the element, suitable for debugging and dumps. It includes template parameters, cv qualifiers, function parameter and return types, and fully-qualified names for all symbols. These strings are too large to compute in productions queries, so they should be used only for dumps and debugging. Feel free to suggest better names for these predicates.
I've updated PrintAST and PrintIR to use these instead of `Function.getFullSignature()`. The biggest advantage of the new predicates is that they handle lambdas and local classes, which `getQualifiedName` and `getFullSignature` do not. This makes IR and AST dumps much more usable for real-world snapshots.
Along the way, I cleaned up some of our handling of `IntegralType` to use a single table for tracking the signed, unsigned, and canonical versions of each type. The canonical part is new, and was necessary for `getTypeIdentityString` so that `signed int` and `int` both appear as `int`.
Methods that are mentioned in a member reference expression should count
as rootdefs for the unused parameter query. Such methods have to match
the functional interface of the reference expression, so it is to be
expected that they will sometimes have to declare parameters that they
don't actually use.
Using the class `ExceptionClass` in combination with a deliberate Cartesian
product can lead to bad join orders, for example
```
EVALUATE NONRECURSIVE RELATION:
Completion::TriedControlFlowElement::getAThrownException_dispred#ff(int this, int result) :-
{1} r1 = JOIN Expr::Expr::getType_dispred#ff_10#join_rhs WITH @integral_type#f ON Expr::Expr::getType_dispred#ff_10#join_rhs.<0>=@integral_type#f.<0> OUTPUT FIELDS {Expr::Expr::getType_dispred#ff_10#join_rhs.<1>}
{1} r2 = JOIN r1 WITH @un_op#f ON r1.<0>=@un_op#f.<0> OUTPUT FIELDS {r1.<0>}
{1} r3 = JOIN r2 WITH Stmt::TryStmt::getATriedElement#ff_1#join_rhs ON r2.<0>=Stmt::TryStmt::getATriedElement#ff_1#join_rhs.<0> OUTPUT FIELDS {r2.<0>}
{2} r4 = JOIN r3 WITH Stmt::ExceptionClass#f CARTESIAN PRODUCT OUTPUT FIELDS {Stmt::ExceptionClass#f.<0>,r3.<0>}
{2} r5 = JOIN r4 WITH System::SystemOverflowExceptionClass#class#f ON r4.<0>=System::SystemOverflowExceptionClass#class#f.<0> OUTPUT FIELDS {r4.<1>,r4.<0>}
```
where the CP is made with `ExceptionClass` rather than `SystemOverflowExceptionClass`
directly.
These predicates currently take a pair of `IRBlock`s - as it stands, at
most one edge can exist from one `IRBlock` to a given other `IRBlock`.
We may need to revisit that assumption and create an `IREdge` IPA type
at some future date
There are a few IR APIs that we've found to be confusingly named. This PR renames them to be more consistent within the IR and with the AST API:
`Instruction.getFunction` -> `Instruction.getEnclosingFunction`: This was especially confusing when you'd call `FunctionAddressInstruction.getFunction` to get the function whose address was taken, and wound up with the enclosing function instead.
`Instruction.getXXXOperand` -> `Instruction.getXXX`. Now that `Operand` is an exposed type, we want a way to get a specific `Operand` of an `Instruction`, but more often we want to get the definition instruction of that operand. Now, the pattern is that `getXXXOperand` returns the `Operand`, and `getXXX` is equivalent to `getXXXOperand().getDefinitionInstruction()`.
`Operand.getInstruction` -> `Operand.getUseInstruction`: More consistent with the existing `Operand.getDefinitionInstruction` predicate.
