libraries: honour SPC_DEFAULT_CFLAGS/CXXFLAGS/LDFLAGS and bug fixes

bzip2, fastlz, jbig, qdbm: thread SPC_DEFAULT_CFLAGS into the
hand-rolled Makefile patches and shell compile commands. Backward
compatible when the env var is empty.

icu: append SPC_DEFAULT_CXXFLAGS/LDFLAGS to runConfigureICU's CXXFLAGS
and LDFLAGS so user flags reach the bundled cxx invocation.

openssl: append user CFLAGS/LDFLAGS after the target name on Configure
so options like -flto and -fprofile-* reach the openssl build.

libheif: rewrite libheif 1.22+'s C-incompatible
`struct heif_bad_pixel { uint32_t row; uint32_t column; };` as a
typedef so C consumers compile.

ncurses: filter the clang/zig-cc "N warning(s) generated." stdout line
out of MKlib_gen.sh's preprocessor pipe before sed turns it into
invalid C in lib_gen.c.

libaom: detect target CPU from SystemTarget instead of hard-coding
generic, fall back to generic only when neither nasm nor yasm is
available, and turn off examples/tests/tools/docs.

src/Package/Library/libheif.php

@@ -24,6 +24,17 @@ class libheif
                 'list(APPEND REQUIRES_PRIVATE "libbrotlidec")' . "\n" . '        list(APPEND REQUIRES_PRIVATE "libbrotlienc")'
             );
         }
+        // libheif 1.22+ ships a C-incompatible header: `struct heif_bad_pixel`
+        $heif_properties = $lib->getSourceDir() . '/libheif/api/libheif/heif_properties.h';
+        if (file_exists($heif_properties)
+            && str_contains(file_get_contents($heif_properties), 'struct heif_bad_pixel { uint32_t row; uint32_t column; };')
+        ) {
+            FileSystem::replaceFileStr(
+                $heif_properties,
+                'struct heif_bad_pixel { uint32_t row; uint32_t column; };',
+                'typedef struct heif_bad_pixel { uint32_t row; uint32_t column; } heif_bad_pixel;'
+            );
+        }
     }
 
     #[BuildFor('Darwin')]