Merge bitcoin/bitcoin#28131: test: Add UBSan -fsanitize=integer suppressions for src/secp256k1 subtree

a747774 Add UBSan `-fsanitize=integer` suppressions for `src/secp256k1` subtree (Hennadii Stepanov)

Pull request description:

  Required for bitcoin/bitcoin#27991 (see the [comment](bitcoin/bitcoin#27991 (comment))) and for the upcoming CMake-based build system.

ACKs for top commit:
  MarcoFalke:
    lgtm ACK a747774

Tree-SHA512: 602fa3ad22d3b0f6981a51358677d2347c92c4c9f59626b497af10f7ba828ede37227d8ee717f089bf33bde5efe0854d53acc89bea46f0955e62b7f22c454d05

Author: fanquake

test/sanitizer_suppressions/ubsan

@@ -12,20 +12,25 @@ unsigned-integer-overflow:*/include/c++/
 unsigned-integer-overflow:FuzzedDataProvider::ConsumeIntegralInRange
 unsigned-integer-overflow:leveldb/
 unsigned-integer-overflow:minisketch/
+unsigned-integer-overflow:secp256k1/
 unsigned-integer-overflow:test/fuzz/crypto_diff_fuzz_chacha20.cpp
 implicit-integer-sign-change:*/include/boost/
 implicit-integer-sign-change:*/include/c++/
 implicit-integer-sign-change:*/new_allocator.h
 implicit-integer-sign-change:crc32c/
 implicit-integer-sign-change:minisketch/
+implicit-integer-sign-change:secp256k1/
 implicit-signed-integer-truncation:*/include/c++/
 implicit-signed-integer-truncation:leveldb/
+implicit-signed-integer-truncation:secp256k1/
 implicit-unsigned-integer-truncation:*/include/c++/
 implicit-unsigned-integer-truncation:leveldb/
+implicit-unsigned-integer-truncation:secp256k1/
 implicit-unsigned-integer-truncation:test/fuzz/crypto_diff_fuzz_chacha20.cpp
 shift-base:*/include/c++/
 shift-base:leveldb/
 shift-base:minisketch/
+shift-base:secp256k1/
 shift-base:test/fuzz/crypto_diff_fuzz_chacha20.cpp
 # Unsigned integer overflow occurs when the result of an unsigned integer
 # computation cannot be represented in its type. Unlike signed integer overflow,