Fix static+shared with generated sources

Clear out the generated sources when reusing object files from the
static library for the shared library to avoid linking them twice.

Change-Id: Idc145f817acc93df4c3b266ac7647299399bc8eb
diff --git a/cc/cc.go b/cc/cc.go
index 51760fc..30228fb 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -2691,6 +2691,7 @@
 							// Optimize out compiling common .o files twice for static+shared libraries
 							mctx.AddInterVariantDependency(reuseObjTag, shared, static)
 							sharedCompiler.baseCompiler.Properties.Srcs = nil
+							sharedCompiler.baseCompiler.Properties.Generated_sources = nil
 						}
 					}
 				} else if linker.buildStatic() {