feat: add multi-arch CI matrix with nan-tagging toggle and 32-bit test suite

Add Travis CI configuration to build and test Wren on both Linux and macOS, for both 32-bit and 64-bit architectures, with and without WREN_NAN_TAGGING defined. Introduce `ci_32` and `ci_64` make targets that build debug/release and C/C++ variants, then run the test suite against each binary using a suffix parameter. Update `util/test.py` with argparse to accept `--suffix` and `suite` arguments, increase test timeout from 2 to 5 seconds, and fix handle leak in `test/api/slots.c` by moving `wrenReleaseHandle` after the conditional block. Replace `fpclassify`/`signbit` checks for infinity/nan in `wrenNumToString` to avoid GCC overflow warnings on 32-bit, double-cast `double` to `uint32_t` in `num_bitwiseNot` to prevent undefined behavior, and relax floating-point comparisons in `test/core/number/sin.wren` and `cos.wren` to use absolute tolerance. Comment out hex literals larger than `0x1000000` in `example/syntax.wren` since they exceed 32-bit range, and bump libuv from v1.8.0 to v1.10.0 for 32-bit build fixes.

example/syntax.wren

@@ -129,8 +129,10 @@ class Literals is SyntaxExample {
     3.14159
     1.0
     -12.34
-    0xdeadbeef
-    0x1234567890ABCDEF
+    0x1000000
+// Literals larger than 0x1000000 are only valid in 64 bit builds
+//    0xdeadbeef
+//    0x1234567890ABCDEF
   }
 
   strings {