Deprecate PHP (#13838)

lib/system/gc_regions.nim

@@ -8,22 +8,7 @@
 
 # "Stack GC" for embedded devices or ultra performance requirements.
 
-when defined(nimphpext):
-  proc roundup(x, v: int): int {.inline.} =
-    result = (x + (v-1)) and not (v-1)
-  proc emalloc(size: int): pointer {.importc: "_emalloc".}
-  proc efree(mem: pointer) {.importc: "_efree".}
-
-  proc osAllocPages(size: int): pointer {.inline.} =
-    emalloc(size)
-
-  proc osTryAllocPages(size: int): pointer {.inline.} =
-    emalloc(size)
-
-  proc osDeallocPages(p: pointer, size: int) {.inline.} =
-    efree(p)
-
-elif defined(useMalloc):
+when defined(useMalloc):
   proc roundup(x, v: int): int {.inline.} =
     result = (x + (v-1)) and not (v-1)
   proc emalloc(size: int): pointer {.importc: "malloc", header: "<stdlib.h>".}