[CMake] Emit LLDB.framework.dSYM to avoid potential name collision with driver's lldb.dSYM

[sgraenitz]

Summary

Emit framework's dSYM bundle as LLDB.framework.dSYM instead of LLDB.dSYM, because the latter could conflict with the driver's lldb.dSYM when emitted in the same directory on case-insensitive file systems.
Requires https://reviews.llvm.org/D60862

[sgraenitz]

This was mostly to illustrate usage of the matching LLVM commit. Unlikely to break something. Post-commit review should be sufficient.

source/API/CMakeLists.txt

 if ( CMAKE_SYSTEM_NAME MATCHES "Windows" )
   add_definitions( -DEXPORT_LIBLLDB )
 endif()
 
 get_property(LLDB_ALL_PLUGINS GLOBAL PROPERTY LLDB_PLUGINS)
 
 if(NOT LLDB_DISABLE_PYTHON)
   get_target_property(lldb_scripts_dir swig_wrapper BINARY_DIR)
   set(lldb_python_wrapper ${lldb_scripts_dir}/LLDBWrapPython.cpp)
 endif()
 
+if(LLDB_BUILD_FRAMEWORK AND LLVM_EXTERNALIZE_DEBUGINFO)
+  set(LLVM_EXTERNALIZE_DEBUGINFO_EXTENSION framework.dSYM)
+endif()
+
 add_lldb_library(liblldb SHARED
   SBAddress.cpp
   SBAttachInfo.cpp
   SBBlock.cpp
   SBBreakpoint.cpp
   SBBreakpointLocation.cpp
   SBBreakpointName.cpp
   SBBreakpointOptionCommon.cpp