[Chromecast] Include all stdlibc++/libgcc symbols in cast_shell.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index e498d3eb467aeb94a8a835357a32be77ddc4f7f1..b0afc9ce3047f538a9635d82a716052d0d15327c 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -4148,7 +4148,7 @@
                       '-g',
                     ],
                     'ldflags': [
-                      # We want to statically link libstdc++/libgcc_s.
+                      # We want to statically link libstdc++/libgcc.
                       '-static-libstdc++',
                       '-static-libgcc',
                     ],
@@ -4160,6 +4160,34 @@
                       '-march=armv7-a',
                       '-mtune=cortex-a8',
                     ],
+                    'target_conditions': [
+                      [ '_type=="executable"', {
+                        # Statically link whole libstdc++ and libgcc in
+                        # executables to ensure only one copy at runtime.
+                        'ldflags': [
+                          # Note executables also get -static-stdlibc++/libgcc.
+                          # Despite including libstdc++/libgcc archives, we
+                          # still need to specify static linking for them in
+                          # order to prevent the executable from having a
+                          # dynamic dependency on them.
+
+                          # Export stdlibc++ and libgcc symbols to force shlibs
+                          # to refer to these symbols from the executable.
+                          '-Wl,--export-dynamic',
+
+                          '-lm', # stdlibc++ requires math.h
+
+                          # In case we redefined stdlibc++ symbols
+                          # (e.g. tc_malloc)
+                          '-Wl,--allow-multiple-definition',
+
+                          '-Wl,--whole-archive',
+                          '-l:libstdc++.a',
+                          '-l:libgcc.a',
+                          '-Wl,--no-whole-archive',
+                        ],
+                      }]
+                    ],
                   }],
                 ],
               }],