vendor: move hash to vendor (#27262)

* vendor: move hash to vendor

* group hashes into one single static lib

vendor/hash/CMakeLists.txt

@@ -0,0 +1,21 @@
+set(TARGET vendor-hash)
+
+llama_add_compile_flags()
+
+set(CMAKE_POSITION_INDEPENDENT_CODE ON)
+
+add_library(${TARGET} STATIC
+    xxhash/xxhash.c
+    sha1/sha1.c
+    sha256/sha256.c
+)
+
+# disable warnings in 3rd party code
+if (CMAKE_C_COMPILER_ID STREQUAL "MSVC")
+    target_compile_options(${TARGET} PRIVATE /w)
+else()
+    target_compile_options(${TARGET} PRIVATE -w)
+endif()
+
+# sha256.c includes "rotate-bits/rotate-bits.h", so consumers get this dir too
+target_include_directories(${TARGET} PUBLIC .)