replace function NewAttrVarId by NewAttrVar, improve caching of uniqueness attribute variable identifiers

before copying the producer, the type variables are modified
to use the type of the producer when updating the types in cases and lets,
otherwise a polymorphic type may be specialized, possibly causing a type error later

to local function n_args_before_producer_and_n_producer_args

add constructors PE_Matches and IsConstructor in module syntax

functions trySimplePatternT and trySimpleExpressionT

use Pattern instead of LhsExpression and Expression instead of RhsExpression

don't create a list of arrays with variable references for each case alternative,
instead allocate a few arrays and reuse these, unify and combine the reference counts after each alternative,
optimize functions unify_counts and combine_counts,
don't sort the case alternatives twice

because the case expression is not identical to the consumer anymore after adding arguments,
don't fold in local function possiblyFoldOuterCase if aci_opt_unfolder is No

remove some unused local variables and functions,
replace field tfi_geni by tfi_n_args_before_producer and tfi_n_producer_args

add record PartitioningInfo

to reduce memory usage of the compiler

if the forwarding pointer has been used and is later replaced by &bottom

keep case_explicit, instead of setting case_explicit to False for all
Case expressions (including cases not usings dynamics) in functions
using dynamics.

use record DefCounts with cons_count, sel_count, mem_count and type_count, instead of separate arguments

prevent unnecessary eval's of partial function calls,
prevent thunk lifting of strict constructors with constant and evaluated arguments

don't generate type representation in TD; functions,
use TypeCodeConstructor and TD_ constructors instead of TypeCodeConstructor.. functions

g
  # (_,a=:b) = g
  = (a,b)