{cdef,reconinter}_test.cc: fix bitwise shift warning

Fixes some clang-19 static analysis warnings of the form:

```
The result of left shift is undefined because the right operand is
negative
```

Bug: 474642915
Change-Id: Iece63e7f972d506c0afee09ab5ff1e3758850f64

test/cdef_test.cc

diff --git a/test/cdef_test.cc b/test/cdef_test.cc
index 6f985f0..df535ab 100644
--- a/test/cdef_test.cc
+++ b/test/cdef_test.cc
@@ -10,6 +10,7 @@
  */
 
 #include <array>
+#include <cassert>
 #include <cstdlib>
 #include <iostream>
 #include <string>
@@ -89,6 +90,7 @@
       ((bsize == BLOCK_8X8) || (bsize == BLOCK_8X4)) ? 8 : 4;
   const int block_height =
       ((bsize == BLOCK_8X8) || (bsize == BLOCK_4X8)) ? 8 : 4;
+  assert(depth >= 8);  // Suppress static analysis warning w/negative depth - 8.
   const unsigned int max_pos = size * size >> static_cast<int>(depth == 8);
   for (pridamping = 3 + depth - 8; pridamping < 7 - 3 * !!boundary + depth - 8;
        pridamping++) {

test/reconinter_test.cc

diff --git a/test/reconinter_test.cc b/test/reconinter_test.cc
index 91bf720..2bfa074 100644
--- a/test/reconinter_test.cc
+++ b/test/reconinter_test.cc
@@ -267,6 +267,8 @@
 
     const int in_precision =
         bd + 2 * FILTER_BITS - conv_params.round_0 - conv_params.round_1 + 2;
+    ASSERT_GT(in_precision, 0);
+    ASSERT_LE(in_precision, 18);
 
     for (int i = 0; i < MAX_SB_SQUARE; i++) {
       src0[i] = rnd_.Rand16() & ((1 << in_precision) - 1);
@@ -308,6 +310,8 @@
 
     const int in_precision =
         bd + 2 * FILTER_BITS - conv_params.round_0 - conv_params.round_1 + 2;
+    ASSERT_GT(in_precision, 0);
+    ASSERT_LE(in_precision, 18);
 
     for (int i = 0; i < MAX_SB_SQUARE; i++) {
       src0[i] = rnd_.Rand16() & ((1 << in_precision) - 1);