CMakeLists.txt: Fix build with ASTCENC_DECOMPRESSOR=ON

When setting that option, the astcenc library isn't called astcenc-foo,
but astcdec-foo. Setting the correct name depending on whether it's set
so usage of ${ASTCENC_LIB_TARGET} further down the CMakeLists.txt
doesn't cause errors.

Author: DanielGibson

CMakeLists.txt

@@ -1196,9 +1196,15 @@ if(NOT ${universal_build})
         set(ASTCENC_ISA_SSE2 OFF)
     endif()
 
+    if(${ASTCENC_DECOMPRESSOR})
+        set(ASTCENC_LIB_NAME astcdec)
+    else()
+        set(ASTCENC_LIB_NAME astcenc)
+    endif()
+
     # "" in the CACHE sets causes use of the existing documentation string.
     if(${ASTCENC_ISA_NONE})
-        set(ASTCENC_LIB_TARGET astcenc-none-static)
+        set(ASTCENC_LIB_TARGET ${ASTCENC_LIB_NAME}-none-static)
         if(CPU_ARCHITECTURE STREQUAL x86_64)
             set(ASTCENC_ISA_AVX2 OFF CACHE BOOL "" FORCE)
             set(ASTCENC_ISA_SSE41 OFF CACHE BOOL "" FORCE)
@@ -1207,27 +1213,27 @@ if(NOT ${universal_build})
     else()
         if(CPU_ARCHITECTURE STREQUAL x86_64)
             if (${ASTCENC_ISA_SSE41})
-                set(ASTCENC_LIB_TARGET astcenc-sse4.1-static)
+                set(ASTCENC_LIB_TARGET ${ASTCENC_LIB_NAME}-sse4.1-static)
                 set(ASTCENC_ISA_AVX2 OFF CACHE BOOL "" FORCE)
                 set(ASTCENC_ISA_SSE2 OFF CACHE BOOL "" FORCE)
             elseif (${ASTCENC_ISA_SSE2})
-                set(ASTCENC_LIB_TARGET astcenc-sse2-static)
+                set(ASTCENC_LIB_TARGET ${ASTCENC_LIB_NAME}-sse2-static)
                 set(ASTCENC_ISA_AVX2 OFF CACHE BOOL "" FORCE)
                 set(ASTCENC_ISA_SSE41 OFF CACHE BOOL "" FORCE)
             else()
-                set(ASTCENC_LIB_TARGET astcenc-avx2-static)
+                set(ASTCENC_LIB_TARGET ${ASTCENC_LIB_NAME}-avx2-static)
                 set(ASTCENC_ISA_AVX2 ON CACHE BOOL "" FORCE)
                 set(ASTCENC_ISA_SSE41 OFF CACHE BOOL "" FORCE)
                 set(ASTCENC_ISA_SSE2 OFF CACHE BOOL "" FORCE)
             endif()
         elseif(CPU_ARCHITECTURE STREQUAL armv8 OR CPU_ARCHITECTURE STREQUAL arm64)
-            set(ASTCENC_LIB_TARGET astcenc-neon-static)
+            set(ASTCENC_LIB_TARGET ${ASTCENC_LIB_NAME}-neon-static)
             set(ASTCENC_ISA_NEON ON)
             set(ASTCENC_ISA_NONE OFF CACHE BOOL "" FORCE)
         else()
             message(STATUS "Unsupported ISA for ASTC on ${CPU_ARCHITECTURE} arch, using ASTCENC_ISA_NONE.")
             set(ASTCENC_ISA_NONE ON CACHE BOOL "" FORCE)
-            set(ASTCENC_LIB_TARGET astcenc-none-static)
+            set(ASTCENC_LIB_TARGET ${ASTCENC_LIB_NAME}-none-static)
         endif()
     endif()
 endif()