android: Don’t compete with NDK API >= 21 over NDK structures

Chrome uses API 16 for 32-bit builds and API 21 for 64-bit builds. The
NDK’s <link.h> provides r_debug and link_map structure definitions only
at API 21 and above. Breakpad used a custom <link.h> to define these
structures only during 64-bit builds, which worked for Chrome’s
purposes. However, other consumers may wish to build Breakpad at
arbitrary API levels without regard to bitness. This alters Breakpad’s
custom <link.h> to correctly check the NDK API level rather than target
CPU bitness.

Likewise for <sys/user.h> on 32-bit x86, which provided a typedef for
user_fpxregs_struct to user_fxsr_struct. API 21 and above, as well as
the unified headers at any API level, always name the structure
user_fpxregs_struct.

Definitions for 64-bit ARM’s user_regs_struct and user_fpsimd_struct
have been removed from Breakpad’s copy of <sys/user.h>. The header
claims that these fallback definitions are only necessary with NDK r10,
which should no longer be in use even by Chromium, which now uses NDK
r12b. This removes the Chromium-specific ANDROID_NDK_MAJOR_VERSION macro
from use entirely.

Fixes https://stackoverflow.com/questions/44141159/ and b/65630828.

Bug: google-breakpad:733
Change-Id: I5841906297cd15b15ce48b73fd8332fd40afc9a0
Reviewed-on: https://chromium-review.googlesource.com/665740
Reviewed-by: Primiano Tucci <primiano@chromium.org>
Reviewed-by: Joshua Peraza <jperaza@chromium.org>
Cr-Mirrored-From: https://chromium.googlesource.com/breakpad/breakpad
Cr-Mirrored-Commit: afa9c52715db1e4bfaa4b01c9aec40cc249b689b
2 files changed