Clean up no_libgcc

no_libgcc is no longer needed anywhere. Move all occurances to no_libcrt
and remove no_libgcc.

Test: build
Change-Id: I6dd49db71d05d7685aa90cc837627f65e6742d6d
diff --git a/cc/testing.go b/cc/testing.go
index d9be900..df7cb78 100644
--- a/cc/testing.go
+++ b/cc/testing.go
@@ -78,7 +78,7 @@
 
 		cc_library {
 			name: "libc",
-			no_libgcc: true,
+			no_libcrt: true,
 			nocrt: true,
 			system_shared_libs: [],
 			recovery_available: true,
@@ -89,7 +89,7 @@
 		}
 		cc_library {
 			name: "libm",
-			no_libgcc: true,
+			no_libcrt: true,
 			nocrt: true,
 			system_shared_libs: [],
 			recovery_available: true,
@@ -100,7 +100,7 @@
 		}
 		cc_library {
 			name: "libdl",
-			no_libgcc: true,
+			no_libcrt: true,
 			nocrt: true,
 			system_shared_libs: [],
 			recovery_available: true,
@@ -111,7 +111,7 @@
 		}
 		cc_library {
 			name: "libc++_static",
-			no_libgcc: true,
+			no_libcrt: true,
 			nocrt: true,
 			system_shared_libs: [],
 			stl: "none",
@@ -120,7 +120,7 @@
 		}
 		cc_library {
 			name: "libc++",
-			no_libgcc: true,
+			no_libcrt: true,
 			nocrt: true,
 			system_shared_libs: [],
 			stl: "none",
@@ -133,7 +133,7 @@
 		}
 		cc_library {
 			name: "libunwind_llvm",
-			no_libgcc: true,
+			no_libcrt: true,
 			nocrt: true,
 			system_shared_libs: [],
 			stl: "none",