Rename aead_chacha20_poly1305 to chachapoly

While the old name is explicit and aligned with the RFC, it's also very long,
so with the mbedtls_ prefix prepended we get a 31-char prefix to each
identifier, which quickly conflicts with our 80-column policy.

The new name is shorter, it's what a lot of people use when speaking about
that construction anyway, and hopefully should not introduce confusion at
it seems unlikely that variants other than 20/1305 be standardised in the
foreseeable future.
diff --git a/tests/suites/test_suite_cipher.function b/tests/suites/test_suite_cipher.function
index e5a252f..92462e5 100644
--- a/tests/suites/test_suite_cipher.function
+++ b/tests/suites/test_suite_cipher.function
@@ -60,7 +60,7 @@
     TEST_ASSERT( mbedtls_cipher_reset( NULL ) == MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
     TEST_ASSERT( mbedtls_cipher_reset( &ctx ) == MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
 
-#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_AEAD_CHACHA20_POLY1305_C)
+#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
     TEST_ASSERT( mbedtls_cipher_update_ad( NULL, buf, 0 )
                  == MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
     TEST_ASSERT( mbedtls_cipher_update_ad( &ctx, buf, 0 )
@@ -77,7 +77,7 @@
     TEST_ASSERT( mbedtls_cipher_finish( &ctx, buf, &olen )
                  == MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
 
-#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_AEAD_CHACHA20_POLY1305_C)
+#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
     TEST_ASSERT( mbedtls_cipher_write_tag( NULL, buf, olen )
                  == MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
     TEST_ASSERT( mbedtls_cipher_write_tag( &ctx, buf, olen )
@@ -195,7 +195,7 @@
     TEST_ASSERT( 0 == mbedtls_cipher_reset( &ctx_dec ) );
     TEST_ASSERT( 0 == mbedtls_cipher_reset( &ctx_enc ) );
 
-#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_AEAD_CHACHA20_POLY1305_C)
+#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
     TEST_ASSERT( 0 == mbedtls_cipher_update_ad( &ctx_dec, ad, sizeof( ad ) - i ) );
     TEST_ASSERT( 0 == mbedtls_cipher_update_ad( &ctx_enc, ad, sizeof( ad ) - i ) );
 #endif
@@ -215,7 +215,7 @@
     TEST_ASSERT( 0 == mbedtls_cipher_finish( &ctx_enc, encbuf + outlen, &outlen ) );
     total_len += outlen;
 
-#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_AEAD_CHACHA20_POLY1305_C)
+#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
     TEST_ASSERT( 0 == mbedtls_cipher_write_tag( &ctx_enc, tag, sizeof( tag ) ) );
 #endif
 
@@ -236,7 +236,7 @@
     TEST_ASSERT( 0 == mbedtls_cipher_finish( &ctx_dec, decbuf + outlen, &outlen ) );
     total_len += outlen;
 
-#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_AEAD_CHACHA20_POLY1305_C)
+#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
     TEST_ASSERT( 0 == mbedtls_cipher_check_tag( &ctx_dec, tag, sizeof( tag ) ) );
 #endif
 
@@ -292,7 +292,7 @@
 #endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
     TEST_ASSERT( 0 == mbedtls_cipher_set_iv( &ctx, iv, 16 ) );
     TEST_ASSERT( 0 == mbedtls_cipher_reset( &ctx ) );
-#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_AEAD_CHACHA20_POLY1305_C)
+#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
     TEST_ASSERT( 0 == mbedtls_cipher_update_ad( &ctx, NULL, 0 ) );
 #endif
 
@@ -340,7 +340,7 @@
 
     TEST_ASSERT( 0 == mbedtls_cipher_reset( &ctx_dec ) );
 
-#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_AEAD_CHACHA20_POLY1305_C)
+#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
     TEST_ASSERT( 0 == mbedtls_cipher_update_ad( &ctx_dec, NULL, 0 ) );
 #endif
 
@@ -416,7 +416,7 @@
     TEST_ASSERT( 0 == mbedtls_cipher_reset( &ctx_dec ) );
     TEST_ASSERT( 0 == mbedtls_cipher_reset( &ctx_enc ) );
 
-#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_AEAD_CHACHA20_POLY1305_C)
+#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
     TEST_ASSERT( 0 == mbedtls_cipher_update_ad( &ctx_dec, NULL, 0 ) );
     TEST_ASSERT( 0 == mbedtls_cipher_update_ad( &ctx_enc, NULL, 0 ) );
 #endif
@@ -484,7 +484,7 @@
     unsigned char ad[200];
     unsigned char tag[20];
     size_t key_len, iv_len, cipher_len, clear_len;
-#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_AEAD_CHACHA20_POLY1305_C)
+#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
     size_t ad_len, tag_len;
 #endif
     mbedtls_cipher_context_t ctx;
@@ -505,7 +505,7 @@
     iv_len = unhexify( iv, hex_iv );
     cipher_len = unhexify( cipher, hex_cipher );
     clear_len = unhexify( clear, hex_clear );
-#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_AEAD_CHACHA20_POLY1305_C)
+#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
     ad_len = unhexify( ad, hex_ad );
     tag_len = unhexify( tag, hex_tag );
 #else
@@ -525,7 +525,7 @@
 #endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
     TEST_ASSERT( 0 == mbedtls_cipher_set_iv( &ctx, iv, iv_len ) );
     TEST_ASSERT( 0 == mbedtls_cipher_reset( &ctx ) );
-#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_AEAD_CHACHA20_POLY1305_C)
+#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
     TEST_ASSERT( 0 == mbedtls_cipher_update_ad( &ctx, ad, ad_len ) );
 #endif
 
@@ -536,7 +536,7 @@
     TEST_ASSERT( finish_result == mbedtls_cipher_finish( &ctx, output + outlen,
                                                  &outlen ) );
     total_len += outlen;
-#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_AEAD_CHACHA20_POLY1305_C)
+#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
     TEST_ASSERT( tag_result == mbedtls_cipher_check_tag( &ctx, tag, tag_len ) );
 #endif