[libc++] Fix invalid escape sequences in Python comments (#94032)

Author: e-kwsm

libcxx/include/__format/escaped_output_table.h

@@ -833,7 +833,7 @@ _LIBCPP_HIDE_FROM_ABI inline constexpr uint32_t __entries[711] = {
 /// more details.
 
 ///
-/// \pre The code point is a valid Unicode code point.
+/// \\pre The code point is a valid Unicode code point.
 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool __needs_escape(const char32_t __code_point) noexcept {
 
   // The entries in the gap at the end.

libcxx/include/__format/width_estimation_table.h

@@ -237,7 +237,7 @@ inline constexpr uint32_t __table_upper_bound = 0x0003fffd;
 
 /// Returns the estimated width of a Unicode code point.
 ///
-/// \pre The code point is a valid Unicode code point.
+/// \\pre The code point is a valid Unicode code point.
 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr int __estimated_width(const char32_t __code_point) noexcept {
   // Since __table_upper_bound contains the unshifted range do the
   // comparison without shifting.

libcxx/utils/generate_escaped_output_table.py

@@ -84,7 +84,7 @@ def compactPropertyRanges(input: list[PropertyRange]) -> list[PropertyRange]:
     return result
 
 
-DATA_ARRAY_TEMPLATE = """
+DATA_ARRAY_TEMPLATE = r"""
 /// The entries of the characters to escape in format's debug string.
 ///
 /// Contains the entries for [format.string.escaped]/2.2.1.2.1

libcxx/utils/generate_width_estimation_table.py

@@ -99,7 +99,7 @@ def compactPropertyRanges(input: list[PropertyRange]) -> list[PropertyRange]:
     return result
 
 
-DATA_ARRAY_TEMPLATE = """
+DATA_ARRAY_TEMPLATE = r"""
 /// The entries of the characters with an estimated width of 2.
 ///
 /// Contains the entries for [format.string.std]/12