This replaces a number of `#include`-s like this:
```
#include "../../../stdlib/public/SwiftShims/Visibility.h"
```
with this:
```
#include "swift/shims/Visibility.h"
```
This is needed to allow SwiftCompilerSources to use C++ headers which include SwiftShims headers. Currently trying to do that results in errors:
```
swift/swift/include/swift/Demangling/../../../stdlib/public/SwiftShims/module.modulemap:1:8: error: redefinition of module 'SwiftShims'
module SwiftShims {
^
Builds.noindex/swift/swift/bootstrapping0/lib/swift/shims/module.modulemap:1:8: note: previously defined here
module SwiftShims {
^
```
This happens because the headers in both the source dir and the build dir refer to SwiftShims headers by relative path, and both the source root and the build root contain SwiftShims headers (which are equivalent, but since they are located in different dirs, Clang treats them as different modules).
These changes caused a number of issues:
1. No debug info is emitted when a release-debug info compiler is built.
2. OS X deployment target specification is broken.
3. Swift options were broken without any attempt any recreating that
functionality. The specific option in question is --force-optimized-typechecker.
Such refactorings should be done in a fashion that does not break existing
users and use cases.
This reverts commit e6ce2ff388.
This reverts commit e8645f3750.
This reverts commit 89b038ea7e.
This reverts commit 497cac64d9.
This reverts commit 953ad094da.
This reverts commit e096d1c033.
rdar://30549345
This patch generates SwiftExports.cmake and SwiftConfig.cmake in the build tree to be compatible with CMake's `find_package` function for importing targets between CMake build trees. This will allow LLDB to consume Swift's targets and infer their transitive dependencies.
