[lldb][TypeSystem][NFCI] Log creation of new TypeSystem instances to expression log (#91985)

We emit `ASTContext` and `TypeSystem` pointers into the `expr` log but
there is no easy way (that I know of) to correlate the pointer value
back to an easily readible form. This patch simply logs the name of the
`TypeSystem` and the associated `ASTContext` into the `expr` channel
whenever we create a new `TypeSystemClang`.

The following is an example of the new log entries:
```
$ grep Created /tmp/lldb.log 
 Created new TypeSystem for (ASTContext*)0x0000000101a2e200 'ASTContext for '/Users/michaelbuch/a.out''
 Created new TypeSystem for (ASTContext*)0x0000000102512a00 'scratch ASTContext'
 Created new TypeSystem for (ASTContext*)0x0000000102116a00 'ClangModulesDeclVendor ASTContext'
 Created new TypeSystem for (ASTContext*)0x00000001022e8c00 'Expression ASTContext for '<user expression 0>''
 Created new TypeSystem for (ASTContext*)0x00000001103e7200 'AppleObjCTypeEncodingParser ASTContext'
 Created new TypeSystem for (ASTContext*)0x00000001103f7000 'AppleObjCDeclVendor AST'
 Created new TypeSystem for (ASTContext*)0x00000001104bfe00 'Expression ASTContext for '<clang expression>''
 Created new TypeSystem for (ASTContext*)0x0000000101f01000 'Expression ASTContext for '<clang expression>''
 Created new TypeSystem for (ASTContext*)0x00000001025d3c00 'Expression ASTContext for '<clang expression>''
 Created new TypeSystem for (ASTContext*)0x0000000110422400 'Expression ASTContext for '<clang expression>''
 Created new TypeSystem for (ASTContext*)0x000000011602c200 'Expression ASTContext for '<user expression 1>''
 Created new TypeSystem for (ASTContext*)0x0000000110641600 'Expression ASTContext for '<clang expression>''
 Created new TypeSystem for (ASTContext*)0x0000000110617400 'Expression ASTContext for '<clang expression>''
```