Eliminate spurious COMPILE_FOR_BPFLOADER_VERSION macro

and make platform bpf.o's target V's platform bpfloader.

Note that all mainline shipped bpf.o's already manually
specify BPFLOADER_MIN_VER.

Test: TreeHugger
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I67b73969def24e1e169c70c5fb1a402bf6e8cabc

staticlibs/native/bpf_headers/include/bpf/bpf_helpers.h

@@ -39,7 +39,13 @@
 // Android U / 14 (api level 34) - various new program types added
 #define BPFLOADER_U_VERSION 37u
 
-// Android V / 15 (api level 35) - this bpfloader should eventually go back to T
+// Android V / 15 (api level 35) - platform only
+// (note: the platform bpfloader in V isn't really versioned at all,
+//  as there is no need as it can only load objects compiled at the
+//  same time as itself and the rest of the platform)
+#define BPFLOADER_V_VERSION 41u
+
+// Android Mainline - this bpfloader should eventually go back to T
 #define BPFLOADER_MAINLINE_VERSION 42u
 
 /* For mainline module use, you can #define BPFLOADER_{MIN/MAX}_VER
@@ -51,7 +57,7 @@
  * In which case it's just best to use the default.
  */
 #ifndef BPFLOADER_MIN_VER
-#define BPFLOADER_MIN_VER COMPILE_FOR_BPFLOADER_VERSION
+#define BPFLOADER_MIN_VER BPFLOADER_V_VERSION
 #endif
 
 #ifndef BPFLOADER_MAX_VER

staticlibs/native/bpf_headers/include/bpf/bpf_map_def.h

@@ -48,9 +48,6 @@
 #define DEFAULT_SIZEOF_BPF_MAP_DEF 32       // v0.0 struct: enum (uint sized) + 7 uint
 #define DEFAULT_SIZEOF_BPF_PROG_DEF 20      // v0.0 struct: 4 uint + bool + 3 byte alignment pad
 
-// By default, unless otherwise specified, allow the use of features only supported by v0.37.
-#define COMPILE_FOR_BPFLOADER_VERSION 37u
-
 /*
  * The bpf_{map,prog}_def structures are compiled for different architectures.
  * Once by the BPF compiler for the BPF architecture, and once by a C++