anv: Don't re-upload shaders when merging
anv: Don't re-upload shaders when merging

Using anv_pipeline_cache_upload_kernel() will re-upload the kernel and
prog_data when we merge caches. Since the kernel and prog_data is
already in the program_stream, use anv_pipeline_cache_add_entry()
instead to only add the entry to the hash table.

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler