Do not emit debug info by default

This basically flips the --noDebug flag to become a --debug flag, so some optimizations, like inlining, aren't skipped by default, which might be unexpected.

tests/compiler/void.optimized.wat

@@ -1,20 +1,11 @@
 (module
- (type $i (func (result i32)))
  (type $v (func))
  (memory $0 0)
  (table $0 1 anyfunc)
- (elem (i32.const 0) $null)
+ (elem (i32.const 0) $start)
  (export "memory" (memory $0))
  (export "table" (table $0))
- (start $start)
- (func $void/anInt (; 0 ;) (type $i) (result i32)
-  i32.const 2
- )
- (func $start (; 1 ;) (type $v)
-  call $void/anInt
-  drop
- )
- (func $null (; 2 ;) (type $v)
+ (func $start (; 0 ;) (type $v)
   nop
  )
 )