[libc++abi] NFC: avoid a -Wunused-parameter warning

[xingxue]

Summary

A -Wunused-parameter warning was introduced by patch rG7f0244afa828 [libc++abi] NFC: adding a new parameter base to functions for calculating… (authored by xingxue). The unused parameter base will be used in a follow-on patch D101298. This patch is to avoid the warning before D101298 is landed.

[ldionne]

libcxxabi/src/cxa_personality.cpp

248–254

[xingxue]

Addressed the comment on fixing the unused parameter base.

[xingxue]

libcxxabi/src/cxa_personality.cpp

248–254

Changed as suggested, thanks!

[ldionne]

Thanks!

libcxxabi/src/cxa_personality.cpp

 /// See Variable Length Data in:
 /// @link http://dwarfstd.org/Dwarf3.pdf @unlink
 /// @param data reference variable holding memory pointer to decode from
 /// @param encoding dwarf encoding type
 /// @param base for adding relative offset, default to 0
 /// @returns decoded value
 static
 uintptr_t
 readEncodedPointer(const uint8_t** data, uint8_t encoding, uintptr_t base = 0)
 {
+    // Parameter 'base' will be used by a follow-on patch. Before that patch
+    // is landed the following statement is to avoid the -Wunused-parameter
+    // warning for now.
+    (void)base;
+
     uintptr_t result = 0;
     if (encoding == DW_EH_PE_omit)
         return result;
     const uint8_t* p = *data;
     // first get value
     switch (encoding & 0x0F)
     {
     case DW_EH_PE_absptr: