Bug 546660 - Clean up mess around LINUX, AVMPLUS_LINUX, __linux__ (r+nnethercote) [kpalacz]

Gcc defines linux on linux, other compilers are supported to the
extent that they emulate gcc's behavior

--HG--
extra : convert_revision : 6bb42c345395fb0a6f779723157f5e43d6669016

js/src/nanojit/CodeAlloc.cpp

@@ -275,7 +275,8 @@ extern  "C" int cacheflush(char *addr, int nbytes, int cache);
 #endif
 
 #ifdef AVMPLUS_SPARC
-#ifdef __linux__  // bugzilla 502369
+// Note: the linux #define provided by the compiler.
+#ifdef linux  // bugzilla 502369
 void sync_instruction_memory(caddr_t v, u_int len)
 {
     caddr_t end = v + len;