Changed all of our synthesized "___clang" functions, types and variables
that get used in expressions over to have a prefix of "$_lldb". Now when we
do name lookups we can easily switch off of the first '$' character to know
if we should look through only our internal (when first char is '$') stuff,
or when we should look through program variables, functions and types.

Converted all of the clang expression code over to using "const ConstString&" 
values for names instead of "const char *" since there were many places that
were converting the "const char *" names into ConstString names and them
throwing them away. We now avoid making a lot of ConstString conversions and
benefit from the quick comparisons in a few extra spots.

Converted a lot of code from LLVM coding conventions into LLDB coding 
conventions.

llvm-svn: 116634

results. The clang opaque type for the expression result will be added to the
Target's ASTContext, and the bytes will be stored in a DataBuffer inside
the new object. The class is named: ValueObjectConstResult

Now after an expression is evaluated, we can get a ValueObjectSP back that
contains a ValueObjectConstResult object.

Relocated the value object dumping code into a static function within
the ValueObject class instead of being in the CommandObjectFrame.cpp file
which is what contained the code to dump variables ("frame variables").

llvm-svn: 115578

expression parser.  There shouldn't be four separate
classes encapsulating a variable.

ClangExpressionVariable is now meant to be the
container for all variable information.  It has
several optional components that hold data for
different subsystems.

ClangPersistentVariable has been removed; we now
use ClangExpressionVariable instead.

llvm-svn: 111600

expression.  It is now possible to do things like this:

(lldb) expr int $i = 5; $i + 1
$0 = (int) 6
(lldb) expr $i + 3
$1 = (int) 8
(lldb) expr $1 + $0
$2 = (int) 14

As a bonus, this allowed us to move printing of
expression results into the ClangPersistentVariable
class.  This code needs a bit of refactoring -- in
particular, ClangExpressionDeclMap has eaten one too
many bacteria and needs to undergo mitosis -- but the
infrastructure appears to be holding up nicely.

llvm-svn: 110896

expression parser.  It is now possible to type:

(lldb) expr int $i = 5; $i + 1
(int) 6
(lldb) expr $i + 2
(int) 7

The skeleton for automatic result variables is
also implemented.  The changes affect:

- the process, which now contains a 
  ClangPersistentVariables object that holds
  persistent variables associated with it
- the expression parser, which now uses
  the persistent variables during variable
  lookup
- TaggedASTType, where I loaded some commonly
  used tags into a header so that they are
  interchangeable between different clients of
  the class

llvm-svn: 110777