[lldb] Alphabetize some CMake files a bit better

No observable behavior change, but makes the generated Plugins.def a bit easier
to read.

Differential Revision: https://reviews.llvm.org/D109367

lldb/source/Plugins/ObjectFile/CMakeLists.txt

@@ -1,8 +1,8 @@
 add_subdirectory(Breakpad)
 add_subdirectory(ELF)
+add_subdirectory(JIT)
 add_subdirectory(Mach-O)
 add_subdirectory(Minidump)
 add_subdirectory(PDB)
 add_subdirectory(PECOFF)
-add_subdirectory(JIT)
 add_subdirectory(wasm)

lldb/source/Plugins/SymbolFile/CMakeLists.txt

@@ -1,5 +1,5 @@
 add_subdirectory(Breakpad)
 add_subdirectory(DWARF)
-add_subdirectory(Symtab)
 add_subdirectory(NativePDB)
 add_subdirectory(PDB)
+add_subdirectory(Symtab)

lldb/source/Plugins/SymbolVendor/CMakeLists.txt

@@ -1,6 +1,7 @@
+add_subdirectory(ELF)
+
 if (CMAKE_SYSTEM_NAME MATCHES "Darwin")
   add_subdirectory(MacOSX)
 endif()
 
-add_subdirectory(ELF)
 add_subdirectory(wasm)