Remove header grouping comments.

This patch removes the comments grouping header includes. They were
added after running IWYU over the LLDB codebase. However they add little
value, are often outdates and burdensome to maintain.

llvm-svn: 346626
diff --git a/lldb/lit/SymbolFile/NativePDB/global-classes.cpp b/lldb/lit/SymbolFile/NativePDB/global-classes.cpp
index 0da3a45..f0fdb56 100644
--- a/lldb/lit/SymbolFile/NativePDB/global-classes.cpp
+++ b/lldb/lit/SymbolFile/NativePDB/global-classes.cpp
@@ -360,4 +360,4 @@
 
 int main(int argc, char **argv) {
   return 0;
-}
\ No newline at end of file
+}