Use stdbool.h and bool for booleans.

src/wren_common.h

@@ -1,8 +1,6 @@
 #ifndef wren_common_h
 #define wren_common_h
 
-// TODO: Use stdbool.h and `bool` for bools instead of int/1/0.
-
 // This header contains macros and defines used across the entire Wren
 // implementation. In particular, it contains "configuration" defines that
 // control how Wren works. Some of these are only used while hacking on
@@ -14,36 +12,36 @@
 // Usually they trade-off a bit of portability for speed. They default to the
 // most efficient behavior.
 
-// If non-zero, then Wren will use a NaN-tagged double for its core value
+// If true, then Wren will use a NaN-tagged double for its core value
 // representation. Otherwise, it will use a larger more conventional struct.
 // The former is significantly faster and more compact. The latter is useful for
 // debugging and may be more portable.
 //
 // Defaults to on.
 #ifndef WREN_NAN_TAGGING
-#define WREN_NAN_TAGGING (1)
+#define WREN_NAN_TAGGING true
 #endif
 
-// If non-zero, the VM's interpreter loop uses computed gotos. See this for
-// more: http://gcc.gnu.org/onlinedocs/gcc-3.1.1/gcc/Labels-as-Values.html
+// If true, the VM's interpreter loop uses computed gotos. See this for more:
+// http://gcc.gnu.org/onlinedocs/gcc-3.1.1/gcc/Labels-as-Values.html
 // Enabling this speeds up the main dispatch loop a bit, but requires compiler
 // support.
 //
 // Defaults to on.
 #ifndef WREN_COMPUTED_GOTO
-#define WREN_COMPUTED_GOTO (1)
+#define WREN_COMPUTED_GOTO true
 #endif
 
 // These flags are useful for debugging and hacking on Wren itself. They are not
 // intended to be used for production code. They default to off.
 
-// Set this to non-zero to stress test the GC. It will perform a collection
-// before every allocation. This is useful to ensure that memory is always
-// correctly pinned.
-#define WREN_DEBUG_GC_STRESS (0)
+// Set this to true to stress test the GC. It will perform a collection before
+// every allocation. This is useful to ensure that memory is always correctly
+// pinned.
+#define WREN_DEBUG_GC_STRESS false
 
-// Set this to non-zero to log memory operations as they occur.
-#define WREN_TRACE_MEMORY (0)
+// Set this to true to log memory operations as they occur.
+#define WREN_TRACE_MEMORY false
 
 // Assertions are used to validate program invariants. They indicate things the
 // program expects to be true about its internal state during execution. If an