Update api.cpp for ANDROID

People are compiling Rcpp on Android so they can work on the bus (and the toilet):

termux/termux-packages#250 (comment)

This patch should help with install Rcpp on that platform. Credit @its-pointless:
https://github.com/its-pointless/gcc_termux/blob/master/R-patches/Rcpp/api.cpp.patch

Author: kendonB

src/api.cpp

@@ -33,7 +33,7 @@ using namespace Rcpp;
 #endif
 
 #if defined(__GNUC__) || defined(__clang__)
-    #if defined(_WIN32) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__CYGWIN__) || defined(__sun) || defined(_AIX) || defined(__MUSL__) || defined(__HAIKU__)
+    #if defined(_WIN32) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__CYGWIN__) || defined(__sun) || defined(_AIX) || defined(__MUSL__) || defined(__HAIKU__) || defined(__ANDROID__)
         // do nothing
     #else
         #include <execinfo.h>
@@ -272,14 +272,14 @@ SEXP rcpp_can_use_cxx11() {				// #nocov start
 // [[Rcpp::register]]
 SEXP stack_trace(const char* file, int line) {
     #if defined(__GNUC__) || defined(__clang__)
-        #if defined(_WIN32) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__CYGWIN__) || defined(__sun) || defined(_AIX) || defined(__MUSL__) || defined(__HAIKU__)
+        #if defined(_WIN32) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__CYGWIN__) || defined(__sun) || defined(_AIX) || defined(__MUSL__) || defined(__HAIKU__) || defined(__ANDROID__)
             // Simpler version for Windows and *BSD
             List trace = List::create(_["file"] = file,
                                       _[ "line"  ] = line,
                                       _[ "stack" ] = "C++ stack not available on this system");
             trace.attr("class") = "Rcpp_stack_trace";
             return trace;
-        #else // ! (defined(_WIN32) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__CYGWIN__) || defined(__sun) || defined(_AIX)
+        #else // ! (defined(_WIN32) || defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__CYGWIN__) || defined(__sun) || defined(_AIX) || defined(__ANDROID__)
 
             /* inspired from http://tombarta.wordpress.com/2008/08/01/c-stack-traces-with-gcc/  */
             const size_t max_depth = 100;