[gcc r14-8225] libstdc++: Avoid -Wmaybe-uninitialized warnings in text_encoding.cc

[Jonathan Wakely <redi@gcc.gnu.org>]

https://gcc.gnu.org/g:ac913d5d518604c5baf7274bed76e3ff8f3e4c08

commit r14-8225-gac913d5d518604c5baf7274bed76e3ff8f3e4c08
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Thu Jan 18 12:40:52 2024 +0000

    libstdc++: Avoid -Wmaybe-uninitialized warnings in text_encoding.cc
    
    These variables are only read from if we haven't reached the end of
    either range, in which case they're guaranteed to be initialized to the
    next alphanumeric character. But we can just initialize them to make the
    compiler happy.
    
    libstdc++-v3/ChangeLog:
    
            * include/bits/unicode.h (__charset_alias_match): Initialize
            __var_a and __var_b.

Diff:
---
 libstdc++-v3/include/bits/unicode.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libstdc++-v3/include/bits/unicode.h b/libstdc++-v3/include/bits/unicode.h
index d025d21f3dd..51bf02e927f 100644
--- a/libstdc++-v3/include/bits/unicode.h
+++ b/libstdc++-v3/include/bits/unicode.h
@@ -1084,7 +1084,7 @@ inline namespace __v15_1_0
     while (true)
       {
 	// Find the value of the next alphanumeric character in each string.
-	unsigned char __val_a, __val_b;
+	unsigned char __val_a{}, __val_b{};
 	while (__ptr_a != __end_a
 		 && (__val_a = __map(*__ptr_a, __num_a)) == 127)
 	  ++__ptr_a;