Fix bug when writing multi-value block type (#1533)

* Fix bug when writing multi-value block type

The block type must be written as an SLEB, not an LEB. We also want it
to be relocatable, so I added a way to write a fixed-size SLEB too
(`WriteS32Leb128WithReloc` and `WriteFixedS32Leb128`).

* Fix ubsan issue

1 files changed, 1 insertions, 1 deletions

diff --git a/src/type.h b/src/type.h
index aaa8aba0..c44b54f1 100644
--- a/src/type.h
+++ b/src/type.h
@@ -33,7 +33,7 @@ using TypeVector = std::vector<Type>;
 class Type {
  public:
   // Matches binary format, do not change.
-  enum Enum {
+  enum Enum : int32_t {
     I32 = -0x01,        // 0x7f
     I64 = -0x02,        // 0x7e
     F32 = -0x03,        // 0x7d