[AsmJIT: Const correctness for Block::data()

Summary:
The C-style cast was discarding const and casting to `(uint8_t *)` at
the same time, causing a warning. Add const and non-const versions of
the method.

Reviewed By: avp

Differential Revision: D61772029

fbshipit-source-id: b03536b5a0dad20caecdf810d4ed475ab00c88ad

external/asmjit/asmjit/src/asmjit/core/zonestack.h

@@ -62,7 +62,9 @@ class ZoneStackBase {
     ASMJIT_INLINE_NODEBUG void setEnd(T* end) noexcept { _end = (void*)end; }
 
     template<typename T>
-    ASMJIT_INLINE_NODEBUG T* data() const noexcept { return (T*)((uint8_t*)(this) + sizeof(Block)); }
+    ASMJIT_INLINE_NODEBUG const T* data() const noexcept { return (const T*)((const uint8_t*)(this) + sizeof(Block)); }
+    template<typename T>
+    ASMJIT_INLINE_NODEBUG T* data() noexcept { return (T*)((uint8_t*)(this) + sizeof(Block)); }
 
     template<typename T>
     ASMJIT_INLINE_NODEBUG bool canPrepend() const noexcept { return _start > data<void>(); }