Fix some clang compilation issues.

Use expected inline behavior with clang.

GCC defaults to -std=gnu90, giving C89 inline semantics with GNU
extensions. Clang defaults to C99. Explicitly use gnu90.

Mark an unused parameter as __unused.

Fix some incorrect casts.

Change-Id: I05b95585d5e3688eda71769b63b6b8a9237bcaf4
diff --git a/libpixelflinger/codeflinger/CodeCache.cpp b/libpixelflinger/codeflinger/CodeCache.cpp
index cfd2b370..d770302 100644
--- a/libpixelflinger/codeflinger/CodeCache.cpp
+++ b/libpixelflinger/codeflinger/CodeCache.cpp
@@ -201,8 +201,8 @@
         mCacheInUse += assemblySize;
         mWhen++;
         // synchronize caches...
-        void* base = assembly->base();
-        void* curr = (uint8_t*)base + assembly->size();
+        char* base = reinterpret_cast<char*>(assembly->base());
+        char* curr = reinterpret_cast<char*>(base + assembly->size());
         __builtin___clear_cache(base, curr);
     }