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.

.travis.yml

@@ -1,7 +1,13 @@
 language: c
+os:
+ - osx
+ - linux
 compiler:
   - gcc
   - clang
+env:
+  - WREN_OPTIONS="" CI_ARCHS="ci_32 ci_64"
+  - WREN_OPTIONS="-DWREN_NAN_TAGGING=0" CI_ARCHS="ci_64"
 # Travis VMs are 64-bit but we compile both for 32 and 64 bit. To enable the
 # 32-bit builds to work, we need gcc-multilib.
 addons:
@@ -10,4 +16,4 @@ addons:
     - gcc-multilib
     - g++-multilib
 sudo: false # Enable container-based builds.
-script: make all && make test
+script: make WREN_CFLAGS=${WREN_OPTIONS} ${CI_ARCHS}