Remove unnecessary references to libunwind.

Bug: 79209464

Test: Builds.

Change-Id: I79f7b0123bc802e3e12d218e888c30dedf5204dc

libbacktrace/Android.bp

diff --git a/libbacktrace/Android.bp b/libbacktrace/Android.bp
index 49027f3..b518630 100644
--- a/libbacktrace/Android.bp
+++ b/libbacktrace/Android.bp
@@ -22,11 +22,6 @@
         "-Werror",
     ],
 
-    // The latest clang (r230699) does not allow SP/PC to be declared in inline asm lists.
-    clang_cflags: ["-Wno-inline-asm"],
-
-    include_dirs: ["external/libunwind/include/tdep"],
-
     target: {
         darwin: {
             enabled: false,
@@ -92,7 +87,6 @@
             shared_libs: [
                 "libbase",
                 "liblog",
-                "libunwind",
                 "libunwindstack",
                 "libdexfile",
             ],