[flang] basic skeleton of assignment analyzer

[flang] basic skeleton of assignment analyzer

remove needless template<> on some function overloads

dodge bogus compiler warning from gcc 8.1.0 only

stricter typing of expressions in symbols

adjust modfile12.f90 expected test results

add Unwrap, massage folding a bit

Use Unwrap to simplify folding

Move KindSelector analysis into expression semantics

fix crash

checkpoint

updates to TypeParamInquiry

support of %KIND type parameter inquiry

equality testing for expressions

checkpoint during PDT implementation

reformat

checkpoint derived type instantiation

checkpoint

resolve merge

debugging failed tests

fix failing resolve37.f90 test

all existing tests pass

clean up all build warnings

fix bug

update copyright dates

fix copyright dates

address review comments

review comment

merge with master after peeling off changes

bugfixing new feature

fix warning from old g++s

tweaks after merging with latest head

more bugfixing

making modfile17.f90 test work

Make kinds into expressions in symbol table types

big refactor for deferring kinds in intrinsic types

modfile17.f90 test passes

clean up TODOs

Simplify types as stored in scopes

Test KIND parameter default init expressions, debug them

Update copyright dates

address comments

remove dead line

address comments

Original-commit: flang-compiler/f18@1f43d0a04813dc02909e9952ee479d13f630df4c
Reviewed-on: https://github.com/flang-compiler/f18/pull/260
Tree-same-pre-rewrite: false