fix: name bcrypt on the MSVC side too — it needed no library list until now

一致性矩阵的两个 Windows 格都失败:

    lld-link: error: undefined symbol: __declspec(dllimport) BCryptGenRandom

⚠️ 而链接行里**一个 `-l` 都没有** —— 不是库里没这个名字,是那段 `ldflags`
挂在 `cfg(all(windows, not(env = "msvc")))` 下,两格都被排除:
一格是 `msvc@system`,另一格 `llvm@20.1.7` 在 Windows 宿主上默认目标
就是 `windows-msvc`。

⭐ MSVC 那侧此前**不需要任何库列表** —— SDK 隐式链接常用的一套,写 `ldflags`
纯属噪声。`openkal.random` 改变了这一点:`bcrypt.lib` 不在两个工具链的
隐式集合里。两侧各写一次,因为它们对库的拼法不同、不共用列表。

⚠️ 我先前判断「Windows SDK 出 bcrypt.lib 所以能解析」——**那句是凭印象**,
与我几小时前查 mingw 目录犯的是同一个错。真正的判据是那个 job 的链接行,
而它一个 `-l` 都没有。

Author: Sunrisepeak

mcpp.toml

@@ -51,6 +51,24 @@ openkal = "0.7.0"
 [target.'cfg(all(windows, not(env = "msvc")))'.build]
 ldflags = ["-lntdll", "-lsynchronization", "-lshell32", "-lkernel32", "-lbcrypt"]
 
+# ⚠️ AND THE SAME ONE LIBRARY ON THE MSVC SIDE, WHICH UNTIL NOW NEEDED NONE.
+#
+# The block above lists the four this implementation calls into, and the MSVC
+# side never needed a list: its SDK links the usual set implicitly, so a
+# `ldflags` entry there would have been noise. `openkal.random` changes that —
+# `BCryptGenRandom` is in `bcrypt.lib`, and that one is not among the implicit
+# set on either the MSVC toolchain or clang's `windows-msvc` target.
+#
+# Measured on the conformance matrix, both Windows rows:
+#
+#     lld-link: error: undefined symbol: __declspec(dllimport) BCryptGenRandom
+#
+# ⚠️ The predicate above is `not(env = "msvc")`, so neither row saw the entry
+# there. The library is named once per side because the two sides spell a
+# library differently and share no list.
+[target.'cfg(all(windows, env = "msvc"))'.build]
+ldflags = ["-lbcrypt"]
+
 # Exceptions and run-time type information, on the one ABI where their absence
 # is asserted.
 #