gallivm: Silence unused variable warnings on release builds.

Reviewed-by: Brian Paul <brianp@vmware.com>

src/gallium/auxiliary/gallivm/lp_bld_arit.c

@@ -1831,6 +1831,8 @@ lp_build_round_altivec(struct lp_build_context *bld,
    assert(lp_check_value(type, a));
    assert(util_cpu_caps.has_altivec);
 
+   (void)type;
+
    switch (mode) {
    case LP_BUILD_ROUND_NEAREST:
       intrinsic = "llvm.ppc.altivec.vrfin";

src/gallium/auxiliary/gallivm/lp_bld_bitarit.c

@@ -182,6 +182,8 @@ lp_build_shl(struct lp_build_context *bld, LLVMValueRef a, LLVMValueRef b)
    assert(lp_check_value(type, a));
    assert(lp_check_value(type, b));
 
+   (void)type;
+
    res = LLVMBuildShl(builder, a, b, "");
 
    return res;