When compiling with lto enabled, use -gline-tables-only instead of -g when debugging is enabled.

-g uses too much memory. -g-line-stables at least lets you get stack traces,
etc.

This is also what clang does IIRC.

Author: gottesmm

cmake/modules/AddSwift.cmake

@@ -136,7 +136,11 @@ function(_add_variant_c_compile_flags)
 
   is_build_type_with_debuginfo("${CFLAGS_BUILD_TYPE}" debuginfo)
   if(debuginfo)
-    list(APPEND result "-g")
+    if(SWIFT_ENABLE_LTO)
+      list(APPEND result "-gline-tables-only")
+    else()
+      list(APPEND result "-g")
+    endif()
   else()
     list(APPEND result "-g0")
   endif()