Be C89 compliant and fix alignment for gcc11

lib/decompress/zstd_decompress_block.c

@@ -932,7 +932,7 @@ ZSTD_decodeSequence(seqState_t* seqState, const ZSTD_longOffset_e longOffsets)
     const ZSTD_seqSymbol* const ofDInfo = seqState->stateOffb.table + seqState->stateOffb.state;
     seq.matchLength = mlDInfo->baseValue;
     seq.litLength = llDInfo->baseValue;
-    U32 const ofBase = ofDInfo->baseValue;
+    {   U32 const ofBase = ofDInfo->baseValue;
         BYTE const llBits = llDInfo->nbAdditionalBits;
         BYTE const mlBits = mlDInfo->nbAdditionalBits;
         BYTE const ofBits = ofDInfo->nbAdditionalBits;
@@ -952,11 +952,11 @@ ZSTD_decodeSequence(seqState_t* seqState, const ZSTD_longOffset_e longOffsets)
 
         /* sequence */
         {   size_t offset;
-#if defined(__clang__)
+    #if defined(__clang__)
             if (LIKELY(ofBits > 1)) {
-#else
+    #else
             if (ofBits > 1) {
-#endif
+    #endif
                 ZSTD_STATIC_ASSERT(ZSTD_lo_isLongOffset == 1);
                 ZSTD_STATIC_ASSERT(LONG_OFFSETS_MAX_EXTRA_BITS_32 == 5);
                 assert(ofBits <= MaxOff);
@@ -992,11 +992,11 @@ ZSTD_decodeSequence(seqState_t* seqState, const ZSTD_longOffset_e longOffsets)
             seq.offset = offset;
         }
 
-#if defined(__clang__)
+    #if defined(__clang__)
         if (UNLIKELY(mlBits > 0))
-#else
+    #else
         if (mlBits > 0)
-#endif
+    #endif
             seq.matchLength += BIT_readBitsFast(&seqState->DStream, mlBits/*>0*/);
 
         if (MEM_32bits() && (mlBits+llBits >= STREAM_ACCUMULATOR_MIN_32-LONG_OFFSETS_MAX_EXTRA_BITS_32))
@@ -1006,11 +1006,11 @@ ZSTD_decodeSequence(seqState_t* seqState, const ZSTD_longOffset_e longOffsets)
         /* Ensure there are enough bits to read the rest of data in 64-bit mode. */
         ZSTD_STATIC_ASSERT(16+LLFSELog+MLFSELog+OffFSELog < STREAM_ACCUMULATOR_MIN_64);
 
-#if defined(__clang__)
+    #if defined(__clang__)
         if (UNLIKELY(llBits > 0))
-#else
+    #else
         if (llBits > 0)
-#endif
+    #endif
             seq.litLength += BIT_readBitsFast(&seqState->DStream, llBits/*>0*/);
 
         if (MEM_32bits())
@@ -1023,6 +1023,7 @@ ZSTD_decodeSequence(seqState_t* seqState, const ZSTD_longOffset_e longOffsets)
         ZSTD_updateFseStateWithDInfo(&seqState->stateML, &seqState->DStream, mlNext, mlnbBits);    /* <=  9 bits */
         if (MEM_32bits()) BIT_reloadDStream(&seqState->DStream);    /* <= 18 bits */
         ZSTD_updateFseStateWithDInfo(&seqState->stateOffb, &seqState->DStream, ofNext, ofnbBits);  /* <=  8 bits */
+    }
 
     return seq;
 }
@@ -1155,7 +1156,7 @@ ZSTD_decompressSequences_body( ZSTD_DCtx* dctx,
         __asm__("nop");
         __asm__(".p2align 5");
         __asm__("nop");
-#  if __GNUC__ >= 9
+#  if __GNUC__ >= 9 && __GNUC__ < 11
         /* better for gcc-9 and gcc-10, worse for clang and gcc-8 */
         __asm__(".p2align 3");
 #  else