meta: Put _mesa_meta_in_progress in the header file

...so that it can be inlined in the two places that call it.

On Bay Trail-D using Fedora 20 compile flags (-m64 -O2 -mtune=generic
for 64-bit and -m32 -march=i686 -mtune=atom for 32-bit), affects
Gl32Batch7:

32-bit: No difference proven at 95.0% confidence (n=120)
64-bit: Difference at 95.0% confidence 1.24042% +/- 0.382277% (n=40)

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Matt Turner <mattst88@gmail.com>

src/mesa/drivers/common/meta.c

@@ -1212,16 +1212,6 @@ _mesa_meta_end(struct gl_context *ctx)
 }
 
 
-/**
- * Determine whether Mesa is currently in a meta state.
- */
-GLboolean
-_mesa_meta_in_progress(struct gl_context *ctx)
-{
-   return ctx->Meta->SaveStackDepth != 0;
-}
-
-
 /**
  * Convert Z from a normalized value in the range [0, 1] to an object-space
  * Z coordinate in [-1, +1] so that drawing at the new Z position with the

src/mesa/drivers/common/meta.h

@@ -446,8 +446,11 @@ _mesa_meta_begin(struct gl_context *ctx, GLbitfield state);
 extern void
 _mesa_meta_end(struct gl_context *ctx);
 
-extern GLboolean
-_mesa_meta_in_progress(struct gl_context *ctx);
+static inline bool
+_mesa_meta_in_progress(struct gl_context *ctx)
+{
+   return ctx->Meta->SaveStackDepth != 0;
+}
 
 extern void
 _mesa_meta_fb_tex_blit_begin(const struct gl_context *ctx,