Add and use constants for the Android API levels.

Test: bionic tests still pass
Change-Id: If1b619cfc9db1d3f5d91f14f2ace71058dca0c4a
diff --git a/libc/include/android/api-level.h b/libc/include/android/api-level.h
index 6dd4c18..c83c18d 100644
--- a/libc/include/android/api-level.h
+++ b/libc/include/android/api-level.h
@@ -43,4 +43,17 @@
 #define __ANDROID_API__ __ANDROID_API_FUTURE__
 #endif
 
+#define __ANDROID_API_G__ 9
+#define __ANDROID_API_I__ 14
+#define __ANDROID_API_J__ 16
+#define __ANDROID_API_J_MR1__ 17
+#define __ANDROID_API_J_MR2__ 18
+#define __ANDROID_API_K__ 19
+#define __ANDROID_API_L__ 21
+#define __ANDROID_API_L_MR1__ 22
+#define __ANDROID_API_M__ 23
+#define __ANDROID_API_N__ 24
+#define __ANDROID_API_N_MR1__ 25
+#define __ANDROID_API_O__ 26
+
 #endif /* ANDROID_API_LEVEL_H */
diff --git a/libc/include/android/legacy_errno_inlines.h b/libc/include/android/legacy_errno_inlines.h
index 93cba1f..8f08074 100644
--- a/libc/include/android/legacy_errno_inlines.h
+++ b/libc/include/android/legacy_errno_inlines.h
@@ -32,7 +32,7 @@
 #include <errno.h>
 #include <sys/cdefs.h>
 
-#if __ANDROID_API__ < 21
+#if __ANDROID_API__ < __ANDROID_API_L__
 
 __BEGIN_DECLS
 
diff --git a/libc/include/android/legacy_fenv_inlines_arm.h b/libc/include/android/legacy_fenv_inlines_arm.h
index a5bb26b..58c49c2 100644
--- a/libc/include/android/legacy_fenv_inlines_arm.h
+++ b/libc/include/android/legacy_fenv_inlines_arm.h
@@ -31,7 +31,7 @@
 
 #include <fenv.h>
 
-#if __ANDROID_API__ < 21 && defined(__arm__)
+#if __ANDROID_API__ < __ANDROID_API_L__ && defined(__arm__)
 
 __BEGIN_DECLS
 
@@ -149,6 +149,6 @@
 
 __END_DECLS
 
-#endif /* __ANDROID_API__ < 21 && defined(__arm__) */
+#endif /* __ANDROID_API__ < __ANDROID_API_L__ && defined(__arm__) */
 
 #endif /* ANDROID_LEGACY_FENV_INLINES_ARM_H */
diff --git a/libc/include/android/legacy_fenv_inlines_mips.h b/libc/include/android/legacy_fenv_inlines_mips.h
index ead697c..10b93c0 100644
--- a/libc/include/android/legacy_fenv_inlines_mips.h
+++ b/libc/include/android/legacy_fenv_inlines_mips.h
@@ -31,7 +31,7 @@
 
 #include <fenv.h>
 
-#if __ANDROID_API__ < 21 && (defined(__mips__) && !defined(__LP64__))
+#if __ANDROID_API__ < __ANDROID_API_L__ && (defined(__mips__) && !defined(__LP64__))
 
 __BEGIN_DECLS
 
@@ -163,6 +163,6 @@
 
 __END_DECLS
 
-#endif /* __ANDROID_API__ < 21 && (defined(__mips__) && !defined(__LP64__)) */
+#endif /* __ANDROID_API__ < __ANDROID_API_L__ && (defined(__mips__) && !defined(__LP64__)) */
 
 #endif /* ANDROID_LEGACY_FENV_INLINES_MIPS_H */
diff --git a/libc/include/android/legacy_signal_inlines.h b/libc/include/android/legacy_signal_inlines.h
index 8ba7894..afdaca8 100644
--- a/libc/include/android/legacy_signal_inlines.h
+++ b/libc/include/android/legacy_signal_inlines.h
@@ -39,7 +39,7 @@
 
 sighandler_t bsd_signal(int signum, sighandler_t handler) __REMOVED_IN(21);
 
-#if __ANDROID_API__ < 21
+#if __ANDROID_API__ < __ANDROID_API_L__
 
 static __inline int sigismember(const sigset_t *set, int signum) {
   /* Signal numbers start at 1, but bit positions start at 0. */
@@ -98,7 +98,7 @@
   return bsd_signal(s, f);
 }
 
-#endif /* __ANDROID_API__ < 21 */
+#endif /* __ANDROID_API__ < __ANDROID_API_L__ */
 
 __END_DECLS
 
diff --git a/libc/include/android/legacy_stdlib_inlines.h b/libc/include/android/legacy_stdlib_inlines.h
index 93554e5..e211de5 100644
--- a/libc/include/android/legacy_stdlib_inlines.h
+++ b/libc/include/android/legacy_stdlib_inlines.h
@@ -32,7 +32,7 @@
 #include <stdlib.h>
 #include <sys/cdefs.h>
 
-#if __ANDROID_API__ < 21
+#if __ANDROID_API__ < __ANDROID_API_L__
 
 __BEGIN_DECLS
 
diff --git a/libc/include/android/legacy_sys_stat_inlines.h b/libc/include/android/legacy_sys_stat_inlines.h
index c08edfa..23a9f07 100644
--- a/libc/include/android/legacy_sys_stat_inlines.h
+++ b/libc/include/android/legacy_sys_stat_inlines.h
@@ -32,7 +32,7 @@
 #include <sys/cdefs.h>
 #include <sys/stat.h>
 
-#if __ANDROID_API__ < 21
+#if __ANDROID_API__ < __ANDROID_API_L__
 
 __BEGIN_DECLS
 
diff --git a/libc/include/android/legacy_sys_wait_inlines.h b/libc/include/android/legacy_sys_wait_inlines.h
index 63343eb..1124f8e 100644
--- a/libc/include/android/legacy_sys_wait_inlines.h
+++ b/libc/include/android/legacy_sys_wait_inlines.h
@@ -34,7 +34,7 @@
 #include <sys/wait.h>
 #include <unistd.h>
 
-#if __ANDROID_API__ < 18
+#if __ANDROID_API__ < __ANDROID_API_J_MR2__
 
 __BEGIN_DECLS
 
@@ -44,6 +44,6 @@
 
 __END_DECLS
 
-#endif /* __ANDROID_API__ < 18 */
+#endif /* __ANDROID_API__ < __ANDROID_API_J_MR2__ */
 
 #endif /* _ANDROID_LEGACY_SYS_WAIT_INLINES_H_ */
diff --git a/libc/include/android/legacy_termios_inlines.h b/libc/include/android/legacy_termios_inlines.h
index 92cb22d..4424bdb 100644
--- a/libc/include/android/legacy_termios_inlines.h
+++ b/libc/include/android/legacy_termios_inlines.h
@@ -35,7 +35,7 @@
 
 #include <linux/termios.h>
 
-#if __ANDROID_API__ < 21
+#if __ANDROID_API__ < __ANDROID_API_L__
 
 __BEGIN_DECLS