Include symbols into install/lib/libcobalt.so (youtube#1857)

To speed up the SB16 development process, include some symbols
(-gline-tables-only) into install/lib/libcobalt.so.

This change affects devel and debug builds only.

b/307760111

starboard/build/config/modular/BUILD.gn

@@ -81,8 +81,8 @@ config("modular") {
     ]
     if (!cobalt_fastbuild) {
       cflags += [
-        # This flag causes an increase in binary size on certain platforms. Refer b/297357707
-        "-g",
+        # Use -gline-tables-only to ease the impact of increased size. Refer b/307760111
+        "-gline-tables-only",
       ]
     }
   } else {

starboard/evergreen/shared/strip_install_target.gni

@@ -41,11 +41,20 @@ template("strip_install_target") {
 
     outputs = [ "$sb_install_output_dir/$install_subdir/$source_name" ]
 
-    args = [
-      strip_executable,
-      "-o",
-      rebase_path(outputs[0], root_out_dir),
-      rebase_path("$root_out_dir/$source_name", root_out_dir),
-    ]
+    # skip stripping to make sure we have some debug symbols. Refer b/307760111
+    if (is_devel) {
+      args = [
+        "cp",
+        rebase_path("$root_out_dir/$source_name", root_out_dir),
+        rebase_path(outputs[0], root_out_dir),
+      ]
+    } else {
+      args = [
+        strip_executable,
+        "-o",
+        rebase_path(outputs[0], root_out_dir),
+        rebase_path("$root_out_dir/$source_name", root_out_dir),
+      ]
+    }
   }
 }