Fixes #647.

functionality.

Now that we automatically name them:

- When -alltypes is on, we no longer need to warn that the multi-decl
  may be rewritten incorrectly.

- When -alltypes is off, we no longer generate constraints to try to
  avoid the need to rewrite the multi-decl at all.

InlineStructDetector did one thing unrelated to its name: it constrained
all union fields wild. Move that logic to ProgramInfo::addVariable, make
the constraint reason message more specific, and update root_cause.c to
expect the new message.

types.

The problem already affected several regression tests for more complex
cases (which expected the extra space), and we didn't seem to notice or
care. But now it is affecting every unchanged variable of that form in a
multi-decl that gets rewritten, and this broke several other regression
tests.

multi-decl rewriting splits them rather than losing them.

Fixes #531
except for a "declaration does not declare anything" compiler warning
that will be addressed by de-nesting the inline structs.

A fixup to "Get the correct form...".

declaration as if it were a definition.

Fixes #644.

The existing regression tests pass, but more testing is needed.

More are still needed.

Delete the test of "Unable to rewrite a typedef with multiple names"
from root_cause.c because that case no longer causes wildness. (I think
it makes sense to just delete the test.)

Now that this case works, add a few tests of it.

In the process, fix a bug that I found in the lookup of the type of an
unchanged typedef.

cases.

- Dealing with Checked C annotations in rewriteMultiDecl
- Use mkString only when BaseTypeRenamed, otherwise use Decl::print
- Factor out buildDeclVar

some cases.

Decl::print code path.

Mainly about possible references to an automatically generated name in a
multi-decl that wasn't rewritten.

This wasn't causing a problem yet, but it seems sensible not to do it.

- Using T in `typedef struct T_struct { ... } T`

- DeclReplacement::getSourceRange removal

Other minor changes.

They are no longer important to have in this PR now that I have switched
unchanged multi-decl members back from mkString to Decl::print in most
cases. I can submit the fixes in a separate PR if we like, or we can
hold off and maybe we'll do a broader overhaul of mkString.

Fix a bug I found that would generate an itype where the unchecked and
checked sides are identical.

Also add documentation of the (narrow) circumstances in which
mkStringForDeclWithUnchangedType interacts with ItypesForExtern to the
code as well as the tests.

…nto inline-struct-fixes

…nto inline-struct-fixes

3C saved the assigned name but neglected to set BaseTypeRenamed or
TagDefToSplit correctly in translation units after the first.

TODO: Add regression tests.

TODO: Add regression tests.

This is much nicer than temporarily mutating the VarDecl to remove the
initializer.

…nto inline-struct-fixes

…nto inline-struct-fixes