typos: fix typos in val64.cpp and val64_tests.cpp

Author: jmoik

src/script/val64.cpp

@@ -906,7 +906,7 @@ bool Val64::div_mod(Val64 &v1, Val64 &v2, divmod_op op)
             // Knuth suggests: (notation reworked to match us, the rest is a
             // direct quote):
 
-            // ... let r* be the remainer.
+            // ... let r* be the remainder.
             // Now test if q* == β, or q* x v2_n-2_ > βr* + v1_n+j-2_:
             // if so, decrease q* by 1, increase r* by v2_n-1_, and
             // repeat this test if r* < β. (The test on v2_n-2_ determines at

src/test/val64_tests.cpp

@@ -737,7 +737,7 @@ BOOST_AUTO_TEST_CASE(val64_mul_span)
     for (bool portable_math : {false, true}) {
         Val64Test::set_force_portable_math(portable_math);
 
-    // Mulitply this by mul, place into res.
+    // Multiply this by mul, place into res.
     for (size_t i = 0; i < 128; i++) {
         for (size_t j = 0; j < 65; j++) {
             Val64Test v64a(vec_setbit(i));