fixup! feat(hexagon): add Hexagon ISA target support

fixup! feat(hexagon): add Hexagon ISA target support

Add BUILD_TARGET_HEXAGON to the preprocessor guard and auto-detection
chain in core/config.h so the target is recognized when compiling with
hexagon-unknown-linux-musl-clang (__hexagon__ predefined macro).

Author: androm3da

core/config.h

@@ -22,7 +22,8 @@
     && !defined(BUILD_TARGET_RISCV32_ILP32D) \
     && !defined(BUILD_TARGET_RISCV32_ILP32F) \
     && !defined(BUILD_TARGET_RISCV32_ILP32) \
-    && !defined(BUILD_TARGET_ARC)
+    && !defined(BUILD_TARGET_ARC) \
+    && !defined(BUILD_TARGET_HEXAGON)
 /* clang-format on */
 #if defined(__x86_64__) || defined(__x86_64)
 #define BUILD_TARGET_X86_64
@@ -52,6 +53,8 @@
 #define BUILD_TARGET_RISCV32_ILP32D
 #elif defined(__arc__)
 #define BUILD_TARGET_ARC
+#elif defined(__hexagon__)
+#define BUILD_TARGET_HEXAGON
 #else
 #error "Build target isn't set"
 #endif