Clean up constructors for SkSL Literal types.

IntLiteral and FloatLiteral each had a pair of public constructors: one
which takes a Type (what type of Int/Float is this?), and another
constructor which takes a Context (assume the generic Float/Int type).

BoolLiteral had a public Context-based constructor, but its Type-based
constructor was private. The Type-based constructor is now public to
match its siblings. This allows us to create Booleans without needing
a Context&, if we have an fBool_Type, and fixes make_unique (which
doesn't like private constructors).

Change-Id: Iffb4980947a73b3a89aa1452cc90dce63620bd67
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/350636
Commit-Queue: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
6 files changed