crucible-llvm-syntax: Concrete syntax for all constructors of MemType

[langston-barrett]

#1113 added support for parsing common integer and pointer types, but the remaining constructors of MemType need dedicated parsing support:

crucible/crucible-llvm-syntax/src/Lang/Crucible/LLVM/Syntax.hs

Lines 177 to 186 in e9b1a01

	parseMemType :: MonadSyntax Atomic m => m MemType
	parseMemType = Parse.describe "LLVM type" $ do
	nm <- Parse.atomName
	case nm of
	Atom.AtomName "i8" -> pure (MemType.IntType 8)
	Atom.AtomName "i16" -> pure (MemType.IntType 16)
	Atom.AtomName "i32" -> pure (MemType.IntType 32)
	Atom.AtomName "i64" -> pure (MemType.IntType 64)
	Atom.AtomName "ptr" -> pure MemType.PtrOpaqueType
	_ -> empty